Replaces Honeywell models: F25, F25F1000, Media Air Filter No. 203719; F35, F35R, F35F1008, Media Air Filter No. FC35A1001; F100, F100F1012, F150, Media Air Filter No. FC100A1026, FC100A1029, & FC100C1009; F200, Media Air Filter No. FC200E1029 & Lennox part #X0583, X8306, X6672. Can replace collection cells in electronic models F25A1043, F25F1042, F35F1008, F100F1012, F150E1026, F200E1029, FC35A1001, FC100A1029, FC200E1029, F50A1074, F50E1158, F50E1174, F50E1281, F50E6074, F50E8054, F50F1073, F50F1099, F55F1011, F58A1018 & F300E1019. Nominal size is 16x25x5 (15 7/8x24 3/4x4 3/8). Carbon-impregnated disposable pleated panel filters. A simple solution for controlling odors & dust particles! Odorous gases & vapors are attracted to & held by the unique properties of the carbon material. Can be installed in any HVAC system. Each filter is individually bagged. Use the bag to dispose of the old filter! Listed and rated by Underwriters Laboratories as U.L. Class 2.