The QuietCare True HEPA Allergen Remover air purifier removes at least 99.97% of common household particles as small as 0.3 microns from the air passing through it such as dust, pollen, mold, spores, tobacco smoke, and cat dander. The carbon pre-filter helps remove common household odors while helping to extend the life of the HEPA filter. This air purifier also features QuietCare sound reducing technology for ultra quiet operation and the Intelli-Check filter monitor to remind you when to replace the pre-filter. or clean the HEPA filter. Recommended for medium to large rooms. Simply vacuum to clean filter. Statistics are from the air that passes through the filter. Overall particle reduction is dependent on many factors including the amount of air processed the pollutant type and the pollutants' introduction rate into the environment.