Resideo Honeywell Air Cleaner Pre-Filter, 12-1/2" x 20" x 5/16", for F50F, F58F, F300A and F300EResideo Honeywell Air Cleaner Pre Filter, 12 1 2" x 20" x 5 16", for F50F, F58F, F300A and F300E Resideo Honeywell Air Cleaner Pre Filter. This pre filter is 12 1 2" x 20" x 5 16". This filter does not include the clips. This filter is sold individually. For use with models F50F1065, F50F1040, F50F1057, F58F1000, F300A2012, F300A2025, F300B2012, F300E1035, F300A series, F300E series, F50F series and F58F series. This filter will not fit F50A or F50E