US Home Filter SC80-20X20X4.375 MERV 13 Honeywell Replacement (2 Pack), 20" x 20" Actual size: 19-7/8" x 19-7/8" x 4-3/8" Merv 13 tested under ashram 52.2-2007 standards Ideal for those with moderate to severe allergies Moisture resistant, heavy-duty frame Galvanized expanded metal backing