Nordic Pure’s 16x25x3 MERV 15 Air Bear Cub Replacement Plus Carbon air filter is meant to replace the air condition filter for any system that requires a 3” depth. Unlike other A/C filters where the nominal and actual sizes differ by a fraction of an inch, the Air Bear Cub Replacement Plus Carbon has a nominal and actual depth of 3 inches exactly. Keep that measurement in mind when you are measuring your furnace air filter. Nordic Pure 3” MERV 15 Trion Air Bear Cub Replacement Plus Carbon filters are made of electrostatically charged synthetic materials with an added flat panel infused with activated charcoal that will attract and capture most airborne particulates in your home or office. Odorous gases and vapors (VOC) are attracted to and held by the activated carbon material while maintaining excellent air flow properties. Our 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. MERV 15 Air Bear Cub Replacement Plus Carbon furnace air conditioner filters are comparable to HVAC filters with the rating of MPR 2800. It is important to note that because of this high filtration and air flow restriction, HVAC systems should be rated to handle filters of MERV 14 and above. Nordic Pure MERV 14 and 15 air filters work great in newer, high efficiency systems that use HEPA filters.