DESC: Infrared Micro Dust Sensor detects pollen, dust and smoke passing through the sensor. Air Quality Monitor-LED display indicates the level of airborne particles passing through the sensor. Filter Check Function has LED lamps that let you know when it's time to change the HEPA and deodorizing filter. Helps maximize performance. Quiet Operation is made possible by the specially designed fan, motor and related parts. HEPA Filter-removes 99.97% of airborne particles 0.3 microns or larger at only Hi, Med and Low speed. Deodorizing Filter-specially treated, activated charcoal makes the deodorizing filter ideal for removing unpleasant odors such as cigarette smoke from the air. Suitable for up to a 12' x 18' room (150CADR: Based on AHAM chart) Slim 6" Wide Design allows the air purifier to fit conveniently and unobtrusively into just about any room.