20x25x5 Lennox X6673 Replacement MERV 8 Furnace Air Filter Qty 4 Nominal Size:20x25x5 Actual Size:19 7/8x24 7/8x4 3/8 Outperforms comparable fiberglass, washable and disposable filters Hypoallergenic and antimicrobial pleated electrostatic filter material Made in the USA