Honeywell Universal 14" Air Purifier Replacement HEPA filter, HRF-F1 / Filter (F) Captures up to 99.97Percent of airborne particles at 0.3 microns Filters should be replaced every 1-5 years depending on use For use with Honeywell air purifier HRF-F1 series: 11520, 12520, 13520, 17200, 18150, 17400, 50150, 50200, 50250, 50300