Holmes HAP9412B-UA HEPA-Type Air Purifier, Mini-Tower Black operates quietly to help remove common household odors and up to 99.% of airborne particle such as pollen, dust, mold, pet dander and smoke, providing relief from odor and irritants in the air. HEPA type filter captures particles as small as 2 microns so you can breathe comfortably. Filter life monitor alerts you when filter changes are needed to maintain maximum performance. Includes one Aer1 filter featuring the odor eliminating power of ARM & HAMMER Baking Soda. Optional ionizer assists in particle removal; 3 speed settings to keep air fresh and pure; Filter-life monitor alerts you when filter changes are needed; Recommended for rooms up to 110 square feet or 10' x 11'.