Uses VortexAir Technology to refresh the air in a room 5x per hour (ideally for rooms up to 219 sq. ft.). Includes a Pre-Filter, H13 True HEPA Filter, and High-Efficiency Activated Carbon Filter to capture smoke, odors, pet dander, and dust. Features "QuietKEAP" technology, making it silent enough for a bedroom (24dB). Has a timer (2/4/6/8 hours) and a "Display Off" button for sleeping. Filter is like new!