The Fellowes® AeraMax® 90 Air Purifier uses 4-stage hospital-type filtration to effectively purify air in small rooms 100 - 200 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 35% more air exchanges during allergy and cold/flu seasons. Backed by a 3-year manufacturer limited warranty.