Filtrete 321-4 Air Filter, 24 in L, 18 in W, 5 MERV, 300 MPR (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 aren't super effective at capturing unwanted particles. Good news - the unique design of the electrostatically charged Filtrete™ pollen air filter attracts - and traps - 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.