With a Nominal size of 20x20x5. Actual Dimensions are 19 3/4 x 19 7/8 x 4 3/8. These filters replace the following part numbers:
- Honeywell F25, filter #203721. Honeywell F35 and F35R, filter # FC35A1019.
- Honeywell F100, & F150, Filter #FC100A1011, and Honeywell F200, Filter #FC200E1011.
- Also be used as a replacement for collection cells in F25F1018, F35F1016, F100F1020, F50A1124, F50A1165, F50E1026, F50E1182, F50E6124, F50E6165, F50E8021, F50E8062, F50F1107, F50F1040, F55A1244, F55A1426, F55A1459, F55F1029, F55F1052, F58A1050, F58F1026 & F300E1027.
- Lennox X0585, X8305, X8308.