Product Description Nordic Pure MERV 12 Pleated AC Furnace Air Filters provide exceptional filtration for both home and commercial environments. Each time air passes through a Nordic Pure pleated furnace air filter, lint, dust, pollen, bacteria, pet dander, dust mites, mold spores, smoke particles, virus carriers, allergens and other contaminants are removed. MERV 12 furnace filters are comparable to HVAC filters with the rating of MPR 1500-1900 or FPR 9. While different companies use different scales to measure the air filter?s efficiency, Nordic Pure chose to follow the industry standard, MERV, as developed by ASHRAE (the American Society of Heating, Refrigeration and Air Conditioner Engineers). No matter the name of the rating, the efficiency of all air filters is rated according to the same criteria as set forth by ASHRAE. Nordic Pure furnace air conditioner filters are manufactured using a heavy duty, moisture resistant beverage board frame. As with all Nordic Pure furnace air conditioner 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 and is better at trapping airborne particles than fiberglass filters. Our attention to the smallest of details results in a healthier living space. 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 (the exact dimensions) than Nominal Size (the name) 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 The Nordic Pure MERV 12 anti-allergen pleated air filter is the ideal filter to reduce airborne contaminants in your home or business. with each pass through your MERV 12 anti-allergen pleated air filter, the air in your environment improves. This electrostatic air filter attracts and captures airborne dust, pollen, mold spores, pet dander, smog, dust mite debris, and baking flour. The MERV 12 anti-allergen pleated air filter is made of synthetic material that will not support the growth of mold and bacteria. Along with the reduction of dust on surfaces, this MERV 12 anti-allergen pleated air filter is a high efficiency filter that will attract and capture the small, allergy-aggravating micro-particles that can cause your family discomfort. The Nordic Pure anti-allergen pleated air filter has a Minimum Efficiency Reporting Value(MERV) of 12 which means that it will collect more than 90-Percent of 3.0-10.0 microns of contaminants, and up to 90-Percent of particles 1.0-3.0 microns. Particles in indoor air are measured in microns, which are 1/1000 of a millimeter. A human hair is about 70 microns wide. The MERV 12 anti-allergen pleated air filter is comparable to a filter with a MPR rating of 1500-1900 and is a great start to creating a healthy environment. with the 4? and 5? air filters there is a wide variance between the nominal size and actual size. Almost ALL filters have a different actual size than the nominal size printed on the filter so it is best if you measure your filter for the EXACT size and compare it to our "Actual Size. This is why we ask you to measure your filter so you aren't surprised if the filter doesn't fit! Our MERV 12 four or five-Inch air filter should be changed at least every 6 months depending on your environment. Changing your air filter at the recommended time will help maintain a healthy environment as well as keeping your air conditioning and heating systems running efficiently.