IMPORTANT Note: Air filters have an actual size that is a fraction of an inch smaller than the standard size (also known as "nominal size"). The size printed on your air filter may NOT be the Actual Size. Nordic Pure’s 16x25x3 MERV 14 Air Bear Cub Replacement filter is meant to replace an air filter for any system that requires a 3” exact depth. Unlike other filters where the nominal and actual sizes differ by a fraction of an inch, the Air Bear Cub Replacement has an actual depth of 3 inches exactly. Keep that measurement in mind when you are measuring your air filter. Nordic Pure 3” MERV 14 Trion Air Bear Cub Replacement filters are made of electrostatically charged synthetic materials that attract and capture most airborne particulates in your home or office. All Nordic Pure pleated HVAC filters are manufactured using a heavy-duty, moisture resistant beverage board frame. The frame has 2 strips of foam tape on 2 sides. There is a metal mesh support grid bonded to the pleats for extra support. Our AC filter media prevents the growth of bacteria or mold, resulting in a much healthier living environment. MERV 14 Air Bear Cub Replacement furnace air filters are comparable to HVAC filters with the rating of MPR 2800. It is important to regularly change your furnace air filters. We recommend that you change your AC air filter every 3 to 6 months, depending on your home or office environment to maintain maximum efficiency and economy.