Change your furnace filter for the last time in 6 full years! This is the only filter you need! Tired of shelling out money for boxes of furnace filters? Then save big by picking up this DuPont electrostatic filter. It effectively traps 91% of pollen, dust and dander-sized particles from .3-10 microns for cleaner indoor air. And when it gets dirty, simply rinse it off and reuse - no replacement parts required! Adjusts to fit 1" filter openings from 14" x 20" to 20" x 25". This is a customer return. Customer returned items have a 7 day return policy.