Nordic Pure 20x25x4/20x25x5 (19 7/8 x 24 7/8 x 4 3/8) Honeywell FC100A1037 Replacement Pleated AC Furnace Air Filters MERV 12, Box of 4 Nominal Size:20x25x5 Actual Size:19 7/8x24 7/8x4 3/8 Comparable to a MPR rating of 1500-1906 Hypoallergenic and antimicrobial pleated electrostatic filter material Made in the USA