Multiple levels of cleaning include a combination of Fine Preliminary Filter that captures large particles, True HEPA Filter that filters micro particles, and activated carbon filter that removes unwanted odors. 

Fine Preliminary Filter - Filters out abrasive substances as a defense for the True HEPA filter.

Activated Carbon Filter - Removes large dust particles, pet dander, and household odors.

True HEPA Filter - Eliminates 99.97% of airborne particles 0.3 micrometers or larger pollen and dust mites and filters air pollution of PM 2.5.

Replace every 3 to 6 months.

Please see pictures for details.