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 4-inch home HVAC filter in your furnace air conditioner or HVAC system. For optimal performance of your heating and cooling system or HVAC system change your 4-inch furnace filter at least once per year. Fits systems calling for a filter thickness of 4.31 and larger. Filtrete Brand is North America?s most trusted brand of HVAC Filters (1). (1) Based on 2024 Sago US Brand Health Survey of Residential HVAC Air Filters (2) % captured is based on ASHRAE 52.2 testing for 0.3 to 1 micron