Description The Winix 114290 Replacement Filter F is a complete one year filter set. The Pre-Filter captures larger particles saving the effectiveness of all other filters. The True HEPA Filter captures 99.97%* of particles and impurities as small as 0.3 microns, including pollen, dust, pet dander and hair, other allergens and cigarette smoke. The Washable AOC™ Carbon Filter is made from activated carbon granules which effectively removes odors from cooking, smoking, and household use. This cassette is sold as one unit and individual components cannot be purchased separately. The genuine Winix Filter F is compatible with Winix Air Purifier unit U450.*Based on an independent laboratory test conducted on particles as small as 0.3 microns in size.