The Filtrete Premium Allergen, Bacteria and Virus filter is our best performing 4-inch filter. Filtrete 20x20x4 MPR 1900 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 MPR 1900 and MERV 13 ratings, your AC filter will help pull and capture countless microparticles – such as pet dander, smoke, bacteria – while letting cleaner air flow through. Your Filtrete Filter will also capture large particles, including lint, pollen and household dust. Use a 12-month pleated 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 furnace filter at least once per year. Fits systems calling for a filter thickness of 4.31 inches and larger. Filtrete Brand is North America's most trusted brand of HVAC Filters (1). Residential use only. (1) Based on 2024 Sago US Brand Health Survey of Residential HVAC Air Filters