Honeywell Odor-Reducing Air Purifier Replacement Pre-Filter, HRF-B1/Filter (B) Nullify Made in USA and Imported Honeywell, filter B, premium odor reducing air Purifier pre-filter, captures larger particles & reduces odors & harmful gases Adds Extra shine to your product Manufactured in China Pre filter Filter B plus Captures harmful gases such as ammonia and other volatile organic compounds Deodorizes the air, reducing odors with activated carbon and zeolite Reduces odors more effectively than standard carbon filters