Compatible to Honeywell 38002 HRF-AP1 Enviracare Universal Replacement Carbon Activated Pre-Filter 16"x48" by CFS Compatible to Honeywell 38002 HRF-AP1 Enviracare Universal Replacement Carbon Activated Pre-Filter 16"x48" by CFS Can be cut to make 1 to 3 pre-filters depending on your model Filter measures 16"x48" Fits virtually all Honeywell Round, QuietCare and SilentComfort Series models