Maximum Coverage: AirDoctor 2000 is the perfect air purifier for small to medium rooms, bedrooms, nurseries, home offices and more. Circulates the air in 305 sq. ft. 4x/hour or in 610 sq. ft. 2x/hour. Superior Air Filtration System: Our UltraHEPA filters are proven to capture 99.99% of airborne particles down to 0.003 microns in size, 100 times smaller than HEPA standards. Adjustable Jet Fans: 30% quieter than traditional air purifiers. 6 fan speeds allow you to customize your purification needs from quiet to boost. Long Lasting Genuine Filters By AirDoctor: To guarantee your AirDoctor performs to tested performance standards always choose genuine AirDoctor brand replacement air. Replace every 6-12 months as needed