Filtrete 20x25x4 MPR 1000 Air Filter, made by 3M, helps capture unwanted particles from your household air to contribute to a cleaner, fresher home environment. Designed with exclusive Filtrete 3 in 1 technology, including an MPR 1000 and MERV 11 rating, your AC filter will help pull and capture countless microparticles such as pet dander, smoke and smog while letting cleaner air flow through. Your Filtrete Filter will also capture large particles, including lint, pollen, mold spores and household dust. Use a 12 month deep pleated 4 inch home HVAC filter in your furnace, air conditioner or HVAC system. Two come in a pack, so keep one filter as backup, or use them in multiple areas. For optimal performance of your heating and cooling system or HVAC system, change your 4 inch furnace filter at least every 12 months. The No. 1 Recommended HVAC Air Filter Brand (1), Filtrete Home Air Filters provide the breakthrough technology needed to change how we clean our air, by filtering out particles both large and invisible, to create a cleaner, healthier home for ourselves and our families. Residential use only. * (1) Based on the 2022 Ipsos US Brand Health Study of Residential HVAC Air Filters.