Nordic Pure MERV 14 Plus Carbon air filters are made of electrostatically charged synthetic materials with an added flat panel infused with activated charcoal that attracts and capture most airborne particulates in your home. It will help eliminate unwanted odors as well as trap most airborne dust and particulate matter for fresh, clean air. Odorous gases and vapors (VOC) are attracted to and held by the activated carbon material while maintaining excellent air flow properties. Our air filters use permanently electrostatically charged material that acts like a magnet to help dust cling to the air filter. The anti-microbial air condition filter media will not permit the growth of bacteria or mold resulting in a healthier environment. MERV 14 Plus Carbon air filters are comparable to air filters with the rating of MPR 2800. Because of the high filtration and air flow restriction, HVAC systems should be rated to handle filters of MERV 14 and above. Our air filters work great in newer, high efficiency systems that use HEPA filters. We recommend that you change your air filter every 30-90 days to maintain maximum efficiency and economy. Important Note:  Almost ALL furnace filters have a different "actual size" than the nominal size printed on the air conditioner filter. It's best if you measure your air filter for the EXACT size and compare it to our "Actual Size" - and then you can be sure your A/C air filter fits!