The Fellowes AeraMax 300 Air Purifier uses 4-stage hospital-type filtration to effectively purify air in large rooms 300 - 600 square feet. The AeraSmart Sensor monitors the air quality and automatically adjusts the fan speed to keep your air purified with ultra-quiet operation. A True HEPA filter with AeraSafe antimicrobial treatment safely removes 99.97% of airborne particles as small as 0.3 microns, including viruses, germs, pollen, ragweed, mold spores, and other allergens, while a carbon filter removes odors and captures large airborne particulates. AeraMax PlasmaTrue Technology is an optional setting that utilizes ionization to help safely remove airborne pollutants. AeraMax Air Purifiers also features Aera+ Mode for 50% more air exchanges during allergy and cold/flu seasons.