4-stage hospital-type filtration. Detects air quality and automatically adjusts the fan speed to keep your air purified. True HEPA filter with antimicrobial treatment safely removes 99.97% of airborne particles as small as 0.3 microns, including allergens, viruses, and cigarette smoke. Proven to capture the airborne flu virus. Carbon filter removes odors and captures large airborne particulates. Aera+™ Mode for allergy and cold/flu seasons. Also features AeraSmart Sensor and PlasmaTrue™ Technology. Ultra-quiet operation. 27.25 x 7.25 x 8.50 in. 12.40 lbs. AHAM and CARB certified. UL Listed. 3 year limited warranty. White.