The AeraMax 290 Air Purifier features a four-stage, hospital-type filtration to effectively clean air in spaces between 300 to 600 square feet. AeraSmart Sensor detects air quality and automatically adjusts the fan speed to keep your air purified. A True HEPA filter with antimicrobial treatment safely removes 99.97 percent of airborne particles as small as 0.3 microns, including allergens, viruses and cigarette smoke. It's also proven effective at capturing the airborne flu virus. Carbon filter removes odors and captures large airborne particulates. PlasmaTrue technology creates an ionized field to help safely remove airborne pollutants. Aera Plus Mode helps you get through allergy and flu seasons. Ultra-quiet operation prevents distracting others in quiet environments.The AeraMax 290 Air Purifier features a four-stage, hospital-type filtration to effectively clean air in spaces between 300 to 600 square feet. AeraSmart Sensor detects air quality and automatically adjusts the fan speed to keep your air purified. A True HEPA filter with antimicrobial treatment safely removes 99.97 percent of airborne particles as small as 0.3 microns, including allergens, viruses and cigarette smoke. It's also proven effective at capturing the airborne flu virus. Carbon filter removes odors and captures large airborne particulates. PlasmaTrue technology creates an ionized field to help safely remove airborne pollutants. Aera Plus Mode helps you get through allergy and flu seasons. Ultra-quiet operation prevents distracting others in quiet environments.