20x20x5 (19.75x19.88x4.38) MERV 11 Aftermarket Honeywell&reg; Replacement Filter (2 Pack) Honeywell F25 Media Air Filter 203721, F35, F35R Media Air Filter FC35A1019, F100, F150 Media Air Filter FC100A1011, F200 Media Air Filter, FC200E1011. Replaces collection cells in electronic models F50A1124, F50A1165, F50E1182, F50E6124, F50E6165, F50E8021, F50E8062, F50F1107, F50F1040, F55A1244, F55A1426, F55A1459, F55F1029, F55F1052, F58A1050, F58F1026, F300E1027 Nominal size 20 x 20 x 5. Actual size 19 3/4 x 19 7/8 x 4 3/8 This is an aftermarket filter.