{"product_id":"21-1-4x36-1-4x1-exact-ez-flow-basic-merv-4-filters-12-pack","title":"21-1\/4x36-1\/4x1 Exact Filters Fiberglass MERV 1-4 (12 pack)","description":"\u003cp\u003eExact Filters® produces this 21-1\/4 x 36-1\/4 x 1″ filter to your measurements, so instead of trimming, taping, or forcing a \"close enough\" size into place, you drop in a filter that fits your 21-1\/4 x 36-1\/4 x 1″ slot the first time.\u003c\/p\u003e\n\n\u003cp\u003eFilter bypass — air slipping past a loose frame instead of through the pleats — is one of the most common reasons a filter underperforms its MERV rating in the real world. A precise fit closes that gap.\u003c\/p\u003e\n\n\u003cp\u003eA MERV 1-4 fiberglass filter is the baseline option for HVAC protection: it stops the larger debris that would foul your coil and blower wheel, at the lowest possible airflow restriction. If your priority is maximum airflow and long blower life, and you're comfortable with frequent replacement, this is the rating that loads your system the least.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eNominal size: 21-1\/4 x 36-1\/4 x 1″\u003c\/li\u003e\n  \u003cli\u003eActual dimensions: 21-1\/4 x 36-1\/4 x 3\/4″\u003c\/li\u003e\n  \u003cli\u003eEfficiency rating: MERV 1-4\u003c\/li\u003e\n  \u003cli\u003eQuantity: 12 filters per carton\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eCommon applications for a 21-1\/4 x 36-1\/4 x 1″ custom filter include retrofit installations, legacy HVAC systems installed before standard sizes were codified, built-in return grilles that were framed to non-standard dimensions, and commercial unit housings that don't match any current off-the-shelf size.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eFeatures\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSold as a 12-pack so you have a full year of replacements on hand\u003c\/li\u003e\n  \u003cli\u003eReplace approximately every 90 days in standard installations; shorter intervals in high-dust, smoky, or heavy-use environments\u003c\/li\u003e\n  \u003cli\u003eMade to your exact 21-1\/4 x 36-1\/4 x 1″ specification — no trimming or taping required at installation\u003c\/li\u003e\n  \u003cli\u003eCardboard frame with reinforced media for structural stability during handling and installation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp style=\"font-family:Arial,Helvetica,sans-serif;font-size:15px;font-weight:bold;color:#1E2D7D;margin:0 0 12px 0;\"\u003eSame 21-1\/4 x 36-1\/4 x 1″ size, different efficiency rating\u003c\/p\u003e\u003ctable width=\"100%\" cellpadding=\"0\" cellspacing=\"8\" style=\"border-collapse:separate;margin:18px 0 0 0;padding:0;\"\u003e\u003ctbody\u003e\u003ctr\u003e\n\u003ctd style=\"width:33.3333%;vertical-align:top;padding:0;\"\u003e\u003ca href=\"\/products\/21-1-4x36-1-4x1-exact-pleated-merv-8-filters-12-pack\" style=\"display:block;background-color:#007B6B;color:#ffffff;text-decoration:none;padding:14px 12px;border-radius:6px;font-family:Arial,Helvetica,sans-serif;font-weight:bold;font-size:15px;line-height:1.25;text-align:center;box-sizing:border-box;\" aria-label=\"See the 21-1\/4 x 36-1\/4 x 1″ filter in MERV 8\" title=\"See the 21-1\/4 x 36-1\/4 x 1″ filter in MERV 8\"\u003eMERV 8\u003cspan style=\"display:block;font-weight:normal;font-size:12px;color:#ffffff;opacity:0.9;margin-top:2px;\"\u003eStandard efficiency\u003c\/span\u003e\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"width:33.3333%;vertical-align:top;padding:0;\"\u003e\u003ca href=\"\/products\/21-1-4x36-1-4x1-exact-pleated-merv-11-filters-12-pack\" style=\"display:block;background-color:#6B3FA0;color:#ffffff;text-decoration:none;padding:14px 12px;border-radius:6px;font-family:Arial,Helvetica,sans-serif;font-weight:bold;font-size:15px;line-height:1.25;text-align:center;box-sizing:border-box;\" aria-label=\"See the 21-1\/4 x 36-1\/4 x 1″ filter in MERV 11\" title=\"See the 21-1\/4 x 36-1\/4 x 1″ filter in MERV 11\"\u003eMERV 11\u003cspan style=\"display:block;font-weight:normal;font-size:12px;color:#ffffff;opacity:0.9;margin-top:2px;\"\u003eEnhanced efficiency\u003c\/span\u003e\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"width:33.3333%;vertical-align:top;padding:0;\"\u003e\u003ca href=\"\/products\/21-1-4x36-1-4x1-exact-pleated-merv-13-filters-12-pack\" style=\"display:block;background-color:#C8102E;color:#ffffff;text-decoration:none;padding:14px 12px;border-radius:6px;font-family:Arial,Helvetica,sans-serif;font-weight:bold;font-size:15px;line-height:1.25;text-align:center;box-sizing:border-box;\" aria-label=\"See the 21-1\/4 x 36-1\/4 x 1″ filter in MERV 13\" title=\"See the 21-1\/4 x 36-1\/4 x 1″ filter in MERV 13\"\u003eMERV 13\u003cspan style=\"display:block;font-weight:normal;font-size:12px;color:#ffffff;opacity:0.9;margin-top:2px;\"\u003eHighest efficiency\u003c\/span\u003e\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\n\n\u003ctable width=\"100%\" cellpadding=\"0\" cellspacing=\"0\" border=\"0\" style=\"border-collapse:separate;margin:24px 0 0 0;padding:0;\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd style=\"background-color:#1E2D7D;border-radius:8px;padding:22px 24px;vertical-align:top;\"\u003e\n\u003cp style=\"font-family:Arial,Helvetica,sans-serif;font-size:18px;font-weight:bold;color:#ffffff;margin:0 0 8px 0;line-height:1.3;\"\u003eNeed 21-1\/4 x 36-1\/4 x 2″ or another depth?\u003c\/p\u003e\n\u003cp style=\"font-family:Arial,Helvetica,sans-serif;font-size:14px;color:#ffffff;margin:0 0 16px 0;line-height:1.55;opacity:0.95;\"\u003eThis size is available in other depths we don't stock online — reach out and our team will quote it for you, typically same business day.\u003c\/p\u003e\n\u003ctable cellpadding=\"0\" cellspacing=\"10\" border=\"0\" style=\"border-collapse:separate;margin:0;padding:0;\"\u003e\u003ctbody\u003e\u003ctr\u003e\n\u003ctd style=\"padding:0;vertical-align:top;\"\u003e\u003ca href=\"tel:+18664698556\" style=\"display:block;background-color:#007B6B;color:#ffffff;text-decoration:none;padding:14px 22px;border-radius:6px;font-family:Arial,Helvetica,sans-serif;font-weight:bold;font-size:16px;line-height:1.2;text-align:center;box-sizing:border-box;white-space:nowrap;\"\u003eCall 866-469-8556\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:0;vertical-align:top;\"\u003e\u003ca href=\"\/pages\/contact-us\" style=\"display:block;background-color:#ffffff;color:#1E2D7D;text-decoration:none;padding:14px 22px;border-radius:6px;font-family:Arial,Helvetica,sans-serif;font-weight:bold;font-size:16px;line-height:1.2;text-align:center;box-sizing:border-box;white-space:nowrap;\"\u003eContact us for a quote\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\n\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e","brand":"Exact Filters","offers":[{"title":"Default Title","offer_id":44083975585914,"sku":"10055D01799 21 1\/4 x 36 1\/4 x 1 E","price":492.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1130\/9462\/files\/ExactM1_1268x1134_00a6dfb4-ab6d-42a2-99a8-501e88311a68.jpg?v=1749318491","url":"https:\/\/www.rememberthefilter.com\/products\/21-1-4x36-1-4x1-exact-ez-flow-basic-merv-4-filters-12-pack","provider":"RememberTheFilter.com","version":"1.0","type":"link"}