AirPro Marreal Elite Smart Air Purifier - Air Quality Sensor w/ Auto Control - HEPA, Activated Carbon, UV, TiO2 Photocatalyst, Ionizer Filters air pollutants and removes odors through sequential stages. Helps eliminate dust, pet dander, tobacco smoke, pollen, mold, bacteria and viruses. SMART sensor measures air quality and automatically increases filtration when needed. Numerical display shows PPM and color codes the air quality: Clean / Blue, Good / Green, Low / Purple and Poor / Red Includes removable filters (TiO2 photocatalyst, activated carbon, HEPA, pre-filter), 2 UV bulbs and an ionizer. AirPro is USA based and provides lifetime support for this highly efficient purifier.