{"title":"20x25x4 Air Filters","description":"\n\u003cp\u003e\u003cstrong\u003eQuick answer:\u003c\/strong\u003e 20x25x4 is the nominal size printed on the frame — the actual size is about 19.5 × 24.5 × 3.625 in. It's a deep-pleat media size for cabinets that take a 4-inch filter. Every filter below is American-made pleated media; pick your MERV rating and pack size.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eNominal vs actual:\u003c\/em\u003e a 20x25x4 filter measures 19.5 × 24.5 × 3.625 in so it slides into a 20x25x4 slot without jamming. If your old filter says 20x25x4, these fit.\u003c\/p\u003e\n\u003ch2\u003eWhich MERV rating for 20x25x4?\u003c\/h2\u003e\n\u003cp\u003eMERV 8 handles everyday dust, lint and pollen. Step up to MERV 10–12 for pet dander and allergies, and MERV 13 or higher for smoke, bacteria and wildfire season. Carbon versions add odor control for cooking, pets and VOCs. Not sure? Read our \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eMERV rating guide\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003e20x25x4 FAQ\u003c\/h2\u003e\n\u003ch3\u003eWhat is a 20x25x4 air filter?\u003c\/h3\u003e\n\u003cp\u003e20x25x4 is the nominal (label) size. The actual size is about 19.5 × 24.5 × 3.625 in, so it fits a 20x25x4 slot with room to slide in. It's a deep-pleat media size for cabinets that take a 4-inch filter. Ironside stocks it in every MERV rating we carry, including activated-carbon versions.\u003c\/p\u003e\n\u003ch3\u003eWhat MERV rating should I get in 20x25x4?\u003c\/h3\u003e\n\u003cp\u003eMERV 8 covers dust and pollen for most homes. Go MERV 10–12 for pets or allergies, MERV 13+ for smoke, bacteria and wildfire season. Higher MERV means finer filtration; change it every 6–12 months.\u003c\/p\u003e\n\u003ch3\u003eDoes shipping cost more if I buy more than one pack?\u003c\/h3\u003e\n\u003cp\u003eNo. Shipping is a flat rate and stays the same on 1, 2 or 3 packs. Stocking a year of filters in one order is the cheapest way to buy — you pay freight once instead of every time.\u003c\/p\u003e\n\u003cp\u003eIronside 20x25x4 filters are made in the USA by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Replace 1-inch filters every 90 days — more often with pets or during allergy and wildfire season. Shipping is flat-rate and stays the same whether you order 1, 2 or 3 packs, so a year's supply costs less per filter than buying one at a time. Every MERV rating we stock in 20x25x4 is below, carbon options included. Built here. Breathe better.\u003c\/p\u003e\n\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is a 20x25x4 air filter?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"20x25x4 is the nominal (label) size. The actual size is about 19.5 × 24.5 × 3.625 in, so it fits a 20x25x4 slot with room to slide in. It's a deep-pleat media size for cabinets that take a 4-inch filter. Ironside stocks it in every MERV rating we carry, including activated-carbon versions.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What MERV rating should I get in 20x25x4?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 8 covers dust and pollen for most homes. Go MERV 10–12 for pets or allergies, MERV 13+ for smoke, bacteria and wildfire season. Higher MERV means finer filtration; change it every 6–12 months.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Does shipping cost more if I buy more than one pack?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"No. Shipping is a flat rate and stays the same on 1, 2 or 3 packs. Stocking a year of filters in one order is the cheapest way to buy — you pay freight once instead of every time.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","products":[{"product_id":"20x25x4-merv-10","title":"20x25x4 MERV 10 Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 MERV 10 pleated air filter delivers allergy \u0026amp; pet defense for your home or office — engineered to keep your HVAC system running clean and your air clear.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures pet dander, mold spores, and fine allergens\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e10\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 10 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 10 captures pet dander, mold spores, fine dust and pollen — the sweet spot for homes with pets or mild allergies.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 10 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 10 captures pet dander, mold spores, fine dust and pollen — the sweet spot for homes with pets or mild allergies.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636214636786,"sku":"20x25x4M10-1","price":37.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636214669554,"sku":"20x25x4M10-2","price":53.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-10.jpg?v=1780790796"},{"product_id":"20x25x4-merv-12","title":"20x25x4 MERV 12 Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 MERV 12 pleated air filter delivers allergy \u0026amp; pet defense for your home or office — engineered to keep your HVAC system running clean and your air clear.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures pet dander, mold spores, and fine allergens\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 12 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 12 captures pet dander, mold spores, fine dust and pollen — the sweet spot for homes with pets or mild allergies.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 12 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 12 captures pet dander, mold spores, fine dust and pollen — the sweet spot for homes with pets or mild allergies.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636214735090,"sku":"20x25x4M12-1","price":38.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636214767858,"sku":"20x25x4M12-2","price":54.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-12.jpg?v=1780790796"},{"product_id":"20x25x4-merv-13-plus-carbon","title":"20x25x4 MERV 13 + Carbon Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 activated-carbon air filter pairs pleated filtration with a carbon layer to trap both airborne particles and the odors that come with cooking, pets, smoke, and VOCs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures everyday particles \u003cb\u003eplus neutralizes household odors\u003c\/b\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e13\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated + activated carbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 13 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 13 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 13 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 13 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636214833394,"sku":"20x25x4M13+C-1","price":45.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636214866162,"sku":"20x25x4M13+C-2","price":81.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-13-plus-carbon.jpg?v=1780790796"},{"product_id":"20x25x4-merv-13","title":"20x25x4 MERV 13 Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 MERV 13 pleated air filter delivers maximum protection for your home or office — engineered to keep your HVAC system running clean and your air clear.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures smoke, bacteria, virus carriers, and wildfire particulates\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e13\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 13 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 13 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 13 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 13 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636214931698,"sku":"20x25x4M13-1","price":41.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636214964466,"sku":"20x25x4M13-2","price":69.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-13.jpg?v=1780790796"},{"product_id":"20x25x4-merv-14-plus-carbon","title":"20x25x4 MERV 14 + Carbon Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 activated-carbon air filter pairs pleated filtration with a carbon layer to trap both airborne particles and the odors that come with cooking, pets, smoke, and VOCs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures everyday particles \u003cb\u003eplus neutralizes household odors\u003c\/b\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e14\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated + activated carbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 14 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 14 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 14 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 14 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215062770,"sku":"20x25x4M14+C-1","price":63.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215095538,"sku":"20x25x4M14+C-2","price":111.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-14-plus-carbon.jpg?v=1780790796"},{"product_id":"20x25x4-merv-14","title":"20x25x4 MERV 14 Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 MERV 14 pleated air filter delivers maximum protection for your home or office — engineered to keep your HVAC system running clean and your air clear.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures smoke, bacteria, virus carriers, and wildfire particulates\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e14\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 14 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 14 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 14 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 14 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215161074,"sku":"20x25x4M14-1","price":55.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215193842,"sku":"20x25x4M14-2","price":94.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-14.jpg?v=1780790796"},{"product_id":"20x25x4-merv-15-plus-carbon","title":"20x25x4 MERV 15 + Carbon Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 activated-carbon air filter pairs pleated filtration with a carbon layer to trap both airborne particles and the odors that come with cooking, pets, smoke, and VOCs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures everyday particles \u003cb\u003eplus neutralizes household odors\u003c\/b\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e15\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated + activated carbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 15 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 15 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 15 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 15 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215292146,"sku":"20x25x4M15+C-1","price":67.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215324914,"sku":"20x25x4M15+C-2","price":122.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-15-plus-carbon.jpg?v=1780790796"},{"product_id":"20x25x4-merv-15","title":"20x25x4 MERV 15 Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 MERV 15 pleated air filter delivers maximum protection for your home or office — engineered to keep your HVAC system running clean and your air clear.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures smoke, bacteria, virus carriers, and wildfire particulates\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e15\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 15 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 15 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 15 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 15 captures fine particles including smoke, bacteria-sized particles and the dust that reaches deep into lungs — the right choice for allergies, asthma and wildfire season.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215390450,"sku":"20x25x4M15-1","price":59.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215423218,"sku":"20x25x4M15-2","price":105.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-15.jpg?v=1780790796"},{"product_id":"20x25x4-merv-7-plus-carbon","title":"20x25x4 MERV 7 + Carbon Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 activated-carbon air filter pairs pleated filtration with a carbon layer to trap both airborne particles and the odors that come with cooking, pets, smoke, and VOCs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures everyday particles \u003cb\u003eplus neutralizes household odors\u003c\/b\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated + activated carbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 7 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 7 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 7 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 7 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215488754,"sku":"20x25x4M7+C-1","price":38.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215521522,"sku":"20x25x4M7+C-2","price":58.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-7-plus-carbon.jpg?v=1780790796"},{"product_id":"20x25x4-merv-7","title":"20x25x4 MERV 7 Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 MERV 7 pleated air filter delivers everyday defense for your home or office — engineered to keep your HVAC system running clean and your air clear.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures dust, lint, pollen, and dust mites\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 7 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 7 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 7 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 7 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215587058,"sku":"20x25x4M7-1","price":36.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215619826,"sku":"20x25x4M7-2","price":52.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-7.jpg?v=1780790796"},{"product_id":"20x25x4-merv-8","title":"20x25x4 MERV 8 Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 MERV 8 pleated air filter delivers everyday defense for your home or office — engineered to keep your HVAC system running clean and your air clear.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures dust, lint, pollen, and dust mites\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 8 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 8 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 8 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 8 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215685362,"sku":"20x25x4M8-1","price":37.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215718130,"sku":"20x25x4M8-2","price":52.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-8.jpg?v=1780790796"},{"product_id":"20x25x4-merv-8-pure-carbon","title":"20x25x4 MERV 8 Pure Carbon Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 activated-carbon air filter pairs pleated filtration with a carbon layer to trap both airborne particles and the odors that come with cooking, pets, smoke, and VOCs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures everyday particles \u003cb\u003eplus neutralizes household odors\u003c\/b\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated + activated carbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 8 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 8 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 8 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 8 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215816434,"sku":"20x25x4PCP-1","price":54.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215849202,"sku":"20x25x4PCP-2","price":81.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-8-pure-carbon.jpg?v=1780790796"},{"product_id":"20x25x4-merv-10-p-plus-carbon","title":"20x25x4 MERV 10 P + Carbon Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 activated-carbon air filter pairs pleated filtration with a carbon layer to trap both airborne particles and the odors that come with cooking, pets, smoke, and VOCs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures everyday particles \u003cb\u003eplus neutralizes household odors\u003c\/b\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e10\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated + activated carbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 10 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 10 captures pet dander, mold spores, fine dust and pollen — the sweet spot for homes with pets or mild allergies.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 10 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 10 captures pet dander, mold spores, fine dust and pollen — the sweet spot for homes with pets or mild allergies.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636215914738,"sku":"20x25x4PM10C-1","price":41.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636215947506,"sku":"20x25x4PM10C-2","price":62.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-10-p-plus-carbon.jpg?v=1780790796"},{"product_id":"20x25x4-merv-12-p-plus-carbon","title":"20x25x4 MERV 12 P + Carbon Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 activated-carbon air filter pairs pleated filtration with a carbon layer to trap both airborne particles and the odors that come with cooking, pets, smoke, and VOCs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures everyday particles \u003cb\u003eplus neutralizes household odors\u003c\/b\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated + activated carbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 12 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 12 captures pet dander, mold spores, fine dust and pollen — the sweet spot for homes with pets or mild allergies.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 12 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 12 captures pet dander, mold spores, fine dust and pollen — the sweet spot for homes with pets or mild allergies.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636216013042,"sku":"20x25x4PM12C-1","price":42.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636216045810,"sku":"20x25x4PM12C-2","price":63.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-12-p-plus-carbon.jpg?v=1780790796"},{"product_id":"20x25x4-merv-8-p-plus-carbon","title":"20x25x4 MERV 8 P + Carbon Air Filter","description":"\u003cp\u003eThe Ironside 20x25x4 activated-carbon air filter pairs pleated filtration with a carbon layer to trap both airborne particles and the odors that come with cooking, pets, smoke, and VOCs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eCaptures everyday particles \u003cb\u003eplus neutralizes household odors\u003c\/b\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eTrue 20x25x4 fit\u003c\/b\u003e — sized to drop straight into standard HVAC and furnace systems\u003c\/li\u003e\n\u003cli\u003eElectrostatically charged, moisture-resistant pleated media\u003c\/li\u003e\n\u003cli\u003eMade in the USA\u003c\/li\u003e\n\u003cli\u003eReplace every 6–12 months for best airflow and efficiency\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cb\u003eBuilt here. Breathe better.\u003c\/b\u003e\u003c\/p\u003e\n\u003cdiv data-ironside-specs\u003e\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e20x25x4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eActual size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eCut to cabinet footprint — see description\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMERV rating\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFilter type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePleated + activated carbon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMedia\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eElectrostatic synthetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eReplace\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eEvery 6–12 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMade in\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSA, by our manufacturing partners\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/20x25x4-air-filters\"\u003eAll 20x25x4 filters →\u003c\/a\u003e · \u003ca href=\"\/blogs\/news\/what-merv-rating-do-i-need\"\u003eWhich MERV do I need?\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eProduct FAQ\u003c\/h2\u003e\n\u003ch3\u003eWill a 20x25x4 filter fit my system?\u003c\/h3\u003e\n\u003cp\u003eIf your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\u003c\/p\u003e\n\u003ch3\u003eWhat does MERV 8 capture?\u003c\/h3\u003e\n\u003cp\u003eMERV 8 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\u003c\/p\u003e\n\u003ch3\u003eHow many packs should I buy?\u003c\/h3\u003e\n\u003cp\u003eShipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\u003c\/p\u003e\n\u003ch3\u003eIs this filter made in the USA?\u003c\/h3\u003e\n\u003cp\u003eYes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\" data-ironside-faq\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will a 20x25x4 filter fit my system?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"If your slot or old filter says 20x25x4, yes — nominal sizes are standardized. This is deep-pleat cabinet media; match the letter code to your cabinet brand.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does MERV 8 capture?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"MERV 8 captures everyday dust, lint and pollen — solid baseline protection for homes without allergy concerns.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many packs should I buy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Shipping is flat-rate and stays the same on 1, 2 or 3 packs — so a year's supply in one order is the cheapest way to buy. A 2-pack covers one to two years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this filter made in the USA?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes — American-made by our manufacturing partners with electrostatic synthetic media in heavy-duty frames. Built here. Breathe better.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Ironside","offers":[{"title":"1 Filter (Single)","offer_id":49636216111346,"sku":"20x25x4PM8C-1","price":39.99,"currency_code":"USD","in_stock":true},{"title":"2-Pack","offer_id":49636216144114,"sku":"20x25x4PM8C-2","price":61.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0820\/6152\/5234\/files\/20x25x4-merv-8-p-plus-carbon.jpg?v=1780790796"}],"url":"https:\/\/getironside.com\/collections\/20x25x4-air-filters.oembed","provider":"Ironside.","version":"1.0","type":"link"}