Oscillating air cleaner removes up to 99.9% up of all microscopic particles 0.3 microns and smaller from the air. Permanent ifD filter may be easily removed and cleaned, ensuring an extra-long, effective-use life. Odor-absorbing pre-filter helps reduce certain household VOCs and airborne gases. Three air cleaning levels (sleep, standard and max-power) take the guesswork out how to most efficiently clean the air of your home. Tower unit fully circulates the air in a closed room five times an hour, greatly reducing the amount of airborne dust, pollen, pet dander, smoke and allergens. Air Cleaner Machine Type: ifD; CADR: 146 (smoke); 150 (dust); 160 (pollen); Maximum Room Size (Square Footage): 225 sq ft; Maximum Room Size: 15 ft x 15 ft.