AeraMax 290 Air Purifier effectively purifies air in a 300 to 600 square foot room with ultra-quiet operation and features the innovative AeraSmart Sensor. This special sensor monitors the air quality and automatically adjusts the fan speed to keep your air purified. The True HEPA filter with AeraSafe antimicrobial treatment safely removes 99.97 percent of airborne particles as small as 0.3 microns, including pollen, ragweed and other allergens, viruses, germs, dust mites, mold spores and odors. The air purifier also includes the Aera Setting for cold/flu and allergy season conditions and a high-impact plastic casing.