HEPA air purifier for rooms 510 square feet or less in size. 330 CADR rating. Upgraded version of the award winning AP51030S unit. These air cleaners quietly and efficiently clean the air you breathe. The true HEPA filter cleans the air passing through it 4.8 times per hour or more depending on the unit and room size. Anyone who is concerned with their air quality or simply wants to keep a room fresh, will feel comfortable with the performance and technology built into a Whispure air purifier. The filter captures 99.97% of particles as small as 0.3 microns from air passing through the filter, capturing airborne allergens such as dust, pet dander, smoke, mold spores, pollen, and fabric fibers. Pre-filter helps remove large particles and reduces odor from the air.