Genuine GeneralAire 20 x 25 x 5 Part # GF 4501 MERV 10 Size 19 5/8" x 24 3/16" x 4 15/16" Case of 3 Furnace Filters generally has a Nominal Size and an Actual Size printed on them. Actual sizes vary widely depending on Manufacturer / Brand for the same Nominal Size. If not sure, please measure the inside of filter cabinet to verify this actual size will fit. Manufactured In North America Case of 3