3M Filtrete Dust Reduction Furnace Filter 20 In. X 20 In. X 1 In. (Pack of 4)

You run a tight ship at home, from floor to ceiling -- and everywhere in between. Unfortunately, ordinary home non-electrostatic air filters arent super effective at capturing unwanted particles. GOOD NEWS: The unique design of the electrostatically charged Filtrete Basic Dust Air Filter attracts -- and trap --more particles from your air through your heating and cooling system, making quality control a breeze. With each cycle through the filter, your indoor air becomes a little bit cleaner. Online purchases are in packages of 4.