This is the air purifier with a four-stage filtration system that eliminates 99.97% of viruses, allergens, and odors. A permanent pre-filter captures large dust particles and allergens while a True HEPA filter at the second stage eliminates 99.97% of airborne particles down to 0.3 microns, including bacteria and mold. The third-stage carbon filter removes odors and an independent study found the fourth stage removes 90% of volatile organic compounds (VOCs emitted by household paint and disinfectants) in just two hours. This patented stage consists of UV light and titanium dioxide media that combine to destroy any remaining bacteria and viruses down to 0.001 microns, including those that cause the common cold and flu. The air purifier filters the air eight times every hour in a 175' sq. room, it has sensors that detect odors and gasses and automatically adjust the fan speed accordingly. With easy-to-use touchscreen controls. UV bulb, HEPA filter, and carbon filter last up to one year; titanium-dioxide media lasts five years. 21" H x 11 1/3" W x 15" L. (16 1/2 lbs.)