The HEPAtech filter has 3 different filters that the air is strained through * Filter 1 is a pre-filter that removes large dust particles, lint, and hair from the dirty air * Filter 2 is the sub-micron filter that captures 99.7 % of all airbore particles as small as .1 microns from the air * Filter 3 is the activated charcoal filter that absorbs and helps eliminate cooking odors, musty air, tobacco odors, and pet related odors as it freshens the air