Filters & Accessories Filters & Accessories Air Purifier FiltersHumidifier Filters Filter Letter AA/A+BCDEFGHJKNRSTUZ Filtration Type HEPAHEPA TypeOdor ReducingPre-Filter Need DustPet Dander/Pet OdorPollenSmoke/Wildfires Pack Size 1-Pack2-Pack3-Pack4-Pack6-PackValue PackYear Supply Kit Premium Gas and Odor Reducing Air Purifier A+ Pre-Filter, HRF-APP1Odor Reducing Carbon Type “A” Pre-Filter, HRF-AP1Gas and Odor Reducing Air Purifier K Pre-Filter – 2 Pack, HRF-K21 Year A Pre-Filter Kit for HEPA Air Purifiers for Extra Large Rooms, HRF-A3001 Year A Pre Filter Kit For HEPA Air Purifiers For Medium Rooms, HRF-A100R Filter and A Pre-Filter Value Pack for HEPA Air Purifiers for Extra Large Rooms, HRF-AVRP300HEPA Air Purifier R Filter and A Pre-Filter Value Pack, HRF-ARVPHoneywell Gas And Odor Reducing Air Purifier B Pre Filter, HRF-B1R Filter and A Pre-Filter Value Pack for HEPA Air Purifiers for Large Rooms, HRF-ARVP200