The HEPA air purifier is 99% efficient at reducing airborne particles such as dust, smoke, pollen, and pet dander, from the air that passes through it. An electronic filter indicator is also included to remind you when to replace the filter. Features dual action HEPA-type filter with activated carbon pre-filter layer to help reduce odors. Recommended for rooms 8.5 feet x 10 feet (85 square feet). Manual control 3 air cleaning levels. AHAM certified. AHAM CADR rating: 55.