DESC: The Photo-Catalytic Oxidation filter is a washable filter that captures and dissolves airborne bacteria, molds, fungi and volatile organic compunds. The UV light tube kills viruses, bacteria and mold that are exposed to the UV-C light energy. The ionizer emits negative ions (small amounts) to enhance the cleaning process while freshening the air. If you're looking for the complete cleaning system, then look no futher than the Hygia 6.0. This unit offers you a dust sensor that will analize the air quality in your home by detecting dust, smoke, pollens and small particles. It will show you the level of dust in the air in your home.