PRODUCT DESCRIPTION Nordic Pure MERV 12 Pleated AC Furnace Air Filters provide exceptional filtration for both home and commercial environments. MERV 12 furnace filters are comparable to HVAC filters with the rating of MPR 1500-1900. Nordic Pure furnace air filters are manufactured using a heavy duty, moisture resistant beverage board frame. As with all Nordic Pure furnace air filters, the material is electrostatically charged to attract unwanted particles. The media used will not promote the growth of bacteria or mold on the air filter. For fresh, clean air in your home and office, it is important to regularly change your AC filter, especially during home improvements. We recommend changing your HVAC furnace filter every 1-3 months, depending on your unique home or office environment. People with pets or those who suffer from allergies should change their A/C air filters more often. Replacing your air filter regularly not only improves indoor air quality, it helps your HVAC unit perform more efficiently. Important Note: Almost all air condition filters have a different Actual Size than Nominal Size printed on the air conditioning filter. It is best to measure the exact size of your A/C filter and compare it to our Actual Size to be sure your HVAC replacement filter fits! FROM THE MANUFACTURER Nordic Pure 16x25x1 MERV 12 Pleated AC Furnace Air Filters: Actual Size: 15-1/2-Inch by 24-1/2-Inch by 3/4-Inch. Changing your air filter is the first step in insuring your HVAC system runs at its optimal level this season. Generally, you should change your 4-Inch air filters every 3 to 6 months. Particles in indoor air are measured in microns, which are 1/1000 of a millimeter. A human hair is about 100 microns wide. A MERV 12 Nordic Pure air filter captures airborne particles as small as 0.3 microns! Nordic Pure air filters, however, the filter media does not permit the growth of bacteria or mold. As a result, it is not necessary to add any potentially irritating chemicals to the air filter.Nordic Pure air filters are made out of an electro statically-charged synthetic material that draws airborne particulates to it like a magnet. Electrostatic filters help trap airborne particles to protect your family from causing pollen, fine dust, smoke particles, airborne plant spores, bacteria, and some viruses.