20x20x1 BoAir Aluminum Electrostatic Furnace Filter

BoAir 5-Stage Permanent, Washable Electrostatic furnace or A/C filter. Lifetime warranty. (20x20x1 filter actually measues exactly 19-5/8 x 19-5/8 x 7/8.) BoAir is considered the best electrostatic filter on the market with high dust arrestance (90%) and low air resistance (0.10 WG) qualities. Drop-in replacemant for your disposable air filter. Features 10X better air filtration than disposable filters and VIBAX MI-50 anti-microbial agent imbedded in filter media to prevent bacteria growth. Heavy duty non-rusting aluminum frame. BoAir filters contain no polyester which makes them easier to wash clean. Genuine BoAir filters are identified by the unique serial number on the label.