BALDWIN FILTERS PA3892 Air Filter, 12 x 20-1/2 in.. More details: Air Filter, Outer Air Filter, Height 20-1/2 In., Length 20-1/2 In., Width 12 In., Outside Dia. 12 In., Boot 12-15/32 In., Includes Lift Tab, (1) Metal Washer, (2) Attached O. Gasket, 7/8 In. (22.2) and 7-7/8 In. (200.0) I. Gasket.