Product Description The Aerostar 20x25x4 MERV 11 Pleated Air Filter (actual size: 19 1/2 x 24 1/2 x 3 3/4 inches) delivers high-efficiency filtration for cleaner, healthier indoor air. Designed for use in residential and commercial HVAC systems, this premium furnace and AC filter features a MERV 11 rating, comparable to MPR 1000-1200 and FPR 7, to capture particles as small as 1.0-3.0 microns. Not only that, but by buying in a multi-pack, you can rest assured that you always have a new filter on hand to make swapping filters out a breeze. These filters are compatible with most standard sized units but for the best fit, we recommend measuring your unit directly or obtaining the actual size from your current filter and to ensure you point the arrows in the direction of the unit for a seamless install. #productDescription { color: #333333; word-wrap: break-word; font-size: small; line-height: initial; margin: 0.5em 0px 0em 25px; } #productDescription_feature_div > h2.default { font-size: medium; margin: 0 0 0.25em; } #productDescription_feature_div > h2.books { color:#333 !important; font-size:21px !important; line-height: 1.3; padding-bottom: 4px; font-weight: normal; margin: 0px; } #productDescription_feature_div > h2.softlines { color:#333 !important; font-size:21px !important; line-height: 1.3; padding-bottom: 4px; font-weight: bold; margin: 0px; } #productDescription > p, #productDescription > div, #productDescription > table { margin: 0 0 1em 0; } #productDescription p { margin: 0em 0 1em 1em; } #productDescription h3 { font-weight: normal; color: #333333; font-size: 1.23em; clear: left; margin: 0.75em 0px 0.375em -15px; } #productDescription table { border-collapse: inherit !important; margin-bottom: 0; } #productDescription table img { max-width: inherit !important; } #productDescription table td { font-size: small; vertical-align: inherit !important; } #productDescription ul li { margin: 0 0 0 20px; } #productDescription ul li ul { list-style-type: disc !important; margin-left: 20px !important; } #productDescription ul ul li { list-style-type: disc !important; margin-left: 20px !important; } #productDescription > ul ul li { list-style-type: disc !important; } #productDescription ul li ul li { margin: 0 0 0 20px; } #productDescription .aplus p { margin: 0 0 1em 0; } #productDescription small { font-size: smaller; } #productDescription.prodDescWidth { max-width: 1000px } P.when('jQuery').execute(function($){ $("#productDescription table").each(function() { var width = $(this).attr('width'); if (width) width += 'px'; else width = 'auto'; $(this).css('width', width); var padding = $(this).attr('cellpadding'); if (padding) padding += 'px'; else padding = '0px'; $(this).css('padding', padding); }); }); #productDescription h3 { margin: 0.75em 0px 0.375em -1px; }