Nordic Pure MERV 12 Plus Carbon air filters are made of a dual material where the MERV rated material has been fused together with a carbon layer. This results in less flow restriction and 33% more surface area for cleaner smelling air. 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. With each pass through the pleated furnace air filter, the air in your living environment improves. Our high efficiency activated carbon AC filter helps eliminate smoke particles, lint, household dust, pollen, dust mites, pet dander, virus carriers, allergens, bacteria, mold spores and other contaminants. All Nordic Pure pleated air filters are manufactured using a heavy duty, moisture resistant beverage board frame. There is a metal mesh support grid bonded to the pleats for extra support. Our air filters use permanently electrostatically charged material that acts like a magnet to help dust cling to the air filter. Our Nordic Pure anti-microbial air condition filter media will not permit the growth of bacteria or mold resulting in a healthier environment. MERV 12 Plus Carbon air filters are comparable to air filters with the MPR rating of 1500-1900 or FPR rating of 9. This high-performance HVAC replacement filter will outperform non-electrostatic fiber-glass filters, washable filters, poly disposable filters, and will help keep your air conditioning and heating systems running efficiently, saving money on utilities and costly maintenance. The effective life of your AC air filter depends on both the inside and outside conditions in which you live. It is important to regularly change your furnace air conditioner filters especially during any home improvements for fresh, clean air in your home or office. 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!