Working in conjunction with its triple filter system, the air purifier pulls in unclean air from the rear passing it through the Pre-filter, HEPA filter, and finally the Photo Catalytic (PCO) filter. These filters are able to capture airborne contaminants as small as 0.3 microns. Only Green Air Pro features this triple air filter system, making the air in your home wonderfully clean. The anion emitters, now moved forward of the fan to the front panel, release trillions of negative ions into your home, attaching themselves to dust particles, and dropping them straight to the floor. This advanced function is ideal for eliminating dust, animal dander, and other particles that float in the air. Left behind is fresh oxygen rich air. Green Air Pro also features a UV lamp. When you need to eliminate strong or offensive odors in your home, the Purifier mode creates activated oxygen (ozone) based upon the square footage of your home. Perfect for eliminating tobacco smoke odors, cooking odors, chemical/cleaning agent odors, paint odors, etc. The activated oxygen will also eradicate pollution embedded in walls, ceilings, floors, carpets, furniture, clothing, countertops....all surfaces in your home. Use Purifier mode (ozone function) when home is unoccupied on units built in timer. Ozone reverts back to oxygen after approx. 30 to 45 minutes. Ozone generation: 360mg/hr per plate. Return home to fresh, clean, oxygen rich air, provided only by the 4 advanced technologies of the Green Air Pro Digital Air Purifier!!