Quietclean Tower Air Purifier Captures Up To 99 Percent Of Ultra-Fine Particles Such As Smoke, Dust, Pollen, Mold Spores, Pet Hair And Dander From Air Passing Through The Filter. It Also Helps Reduce Odors And Vocs. Air Purifier Includes A Permanent, Washable Ifd Filter And An Installed, Washable Pre-Filter For Easy Maintenance. Filter Check/Reset Light Reminds You When It'S Time To Change Your Filter. Filters Should Be Cleaned Every 3 Months For Optimal Filtration. Features Include Three Cleaning Levels And Optional Oscillation. Quiet Operation Enables Use While You Sleep, Watch Tv Or Work. Tower Design Circulates Air In A 170 Square Foot Room Up To 4.8 Times Per Hour. Electronic, Push-Button Controls And Dimmer Feature Simplify The Operation. Air Purifier Is Aham Verified And Is Independently Tested For Efficiency In Reducing Smoke, Dust And Pollen. Reach-Through Handle Allows Easy Portability From Room To Room.