The Honeywell True Tower Allergen Remover filter captures up to 99.97% of microscopic allergens such as mold spores, pollen, dust, smoke and pet dander as small as 0.3 microns. It also captures certain airborne germs. It is recommended for medium to large rooms - AHAM Verifide for a 170 sq. ft. (13'x13') room size. It has easy tap electronic controls, including: 3 air cleaning levels plus Turbo Clean setting, 2, 4 & 8 hour timer, electronic filter replacement indicators. 1) Circulates room air 5 times every hour, 2) Activated carbon pre-filter helps rduce unpleasant odors, 3) Energy Star rated, Filter: HRF-B. Black