The Clean Comfort® CC-HEPAUV Return Duct or Return Remote Collar Mount system has dual UVC germicidal lights with three stages of filtration, a ventilator, a speed selection switch, and a cabinet enclosure system. After passing through the dual UVC germicidal lights, the ventilator pulls air through the pre-filter and then through the impregnated carbon pad for odor control. Finally, the last stage of filtration is the HEPA filter, which removes 99.97% of particles 0.3um in size that pass through the filter*.