The Airgle 150 is our room sized air purifier using Nano Filter technology, and has been designed to efficiently and effectively clean the air in an area up to 450 square feet. The Airgle 150 air purifier provides an efficient and cost effective method of removing indoor air pollutants. By using a powerful 4-speed fan with ultra quiet motor technology, air is passed through a four stage filtration system consisting of a pre-filter which catches large dust particles and hair, a HEPA filter which removes 99.97% of particulates larger than 0.3 microns, an activated carbon filter which eliminates odors, and a sterilization filter which destroys bacteria. Source: Airgle http://www.airgle.com