Nordic Pure's air filters are pleated and electro statically charged and have a high efficiency rating. The electrostatic charge of the air filters works as a magnet and draw airborne particles to them. This helps protect your family from pollen, fine dust, tobacco and cooking smoke, airborne plant spores, bacteria and some viruses. Our non-woven synthetic filter media will not support the growth of mold or bacteria, keeping your home healthier. Air filters are ranked in a minimum efficiency rating value (MERV) system. The higher the MERV rating, the better the air filter can filter out all airborne particulates. Remember not all HVAC systems can handle the higher MERV ratings. Filters that have received a rating of MERV 7-12 are great for all HVAC systems. However, MERV ratings of 13-16 are able to remove and capture smaller particle sizes even before the air filter starts to become dirty and are recommended for newer units. We manufacture most any size disposable home air filter in 1/2-Inch 1-Inch, 2-Inch, 4-Inch, 5-Inch and 6-Inch thickness. The printed size on the side of your air filters may be the nominal size so it is best to physically measure your filters with a ruler or tape to get the EXACT measurements of your home air filters within 1/8 of an inch on the length and width. Consult your HVAC system's operating manual for information. Nordic Pure recommends that you replace your filters every 1 to 6 months. That way, our filters will help your HVAC system to continue running to its best capacity. Nordic Pure has been manufacturing air filters since 1960 at our plant in Oklahoma. We are proud to be offering a MADE IN THE USA product.