MEDIA REPLACEMENT FILTER,20 In. X 20 In.,MERV, Filter Type Panel, Performance Rating MERV 13, Actual Depth 4 3/8 in, Actual Height 20 3/16 in, Actual Width 20 7/16 in, Number of Filters 1, Nominal Depth 6 in, Nominal Height 20 in, Nominal Width 20 in, Filters Down To 0.3 micron, Filter Efficiency 63 to 99 Percent, Standards Refrigerating and Air-Conditioning Engineers Standard 522-1999