Polluted air first passes through Alen's washable Pre-Filter to capture large particles, extending the life of the filter.  In the second layer, air moves through a unique, H12 Grade HEPA filter that attracts and captures dust, pollen, pet dander, mold spores and other airborne pollutants.  In the final layer, clean air passes through a layer of Alen's Activated Carbon, reducing light odors and chemicals commonly found in the air from cleaning products, smoke, cooking, pets and various other household materials.