Genuine Original Part # M2-1056 MERV 11 Size 20x20x5 (Actual Size: 20-1/4" x 20-3/4" x 5-1/4") 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 Canada Case of 3