Capture 99.97 Percent of Airborne Asthma and Allergy-Triggering Contaminants With the Kenmore Medium Room Air Purifier The Kenmore Air Purifier can reduce airborne particles in rooms up to 280 square feet using the ultra-effective, Two-Stage Filtration System which captures 99.97 percent of particles as small as 0.3 microns and helps eliminate allergens and pollutants such as pollen, pet dander and dust. A separate charcoal pre-filter traps odors and pre-cleans the air. The third cleaning stage consists of the optional ionizer to assist in particle removal and air freshening. Electronics have been smartly utilized in the Kenmore Medium Room Air Purifier for your convenience. HEPA filter and pre-filter change indicators inform you when to swap in the new one so you get the most of every filter. You can also customize fan speed, and program the timer or activate the optional ionizer with the touch of a button. Creating less than 29db on low speed, this air purifier is quiet enough for a nursery, bedroom, or library, and can work either lying down or standing upright to work with the space you have.