The Honeywell HEPA Air Purifier is the #1 brand recommended by allergists. The True HEPA filter captures up to 99.97% of microscopic allergens, 0.3 microns and larger. It helps capture certain airborne germs. The carbon pre-filter helps reduce unpleasant odors, VOC's and certain gases while trapping larger particles such as dust, lint, fibers & pet fur. The easy tap electronic controls have 4 air cleaning levels: Germ, Allergen, General Clean and Turbo and an electronic filter replacement indicator. It also has auto shut-off timer; 2, 4, or 8 hrs and control panel adjustable lighting (bright/dim/off). It is ENERGY STAR qualified and has 5 room air changes per hour. It is recommended for extra large rooms up to 465 sq. ft.