Carbon Pre-Filter 4-pack for Homedics AF-100FL 4-pack of Carbon Activated Pre-Filters Made in the USA from premium BulkFilter Brand filter material For use with HoMedics hypoallergenic HEPA Air Cleaners AF-100 Hepa Filter AF-100FL Carbon Activated filters extend the life of the hepa filter and remove common household odors Each Carbon Pre-Filter measures 13"x11.6"x.2"