20x25x4 Electrostatic Washable Furnace and Ac Filter 19 1/2 x 24 1/2 x 3 5/8 Replaces 20x25x4 disposable media air filters Actual size: 19-1/2 x 24-1/2 x-3 5/8 Electrostatic, Washable, Permanent Filter Non-Rusting Stainless Frame, Lifetime Warranty 100s+ Sizes available - see our other listings