DESC: The beauty of the Air-O-Swiss 2055D air washer is that in addition to being a humidifier, it traps pet hair, large dust and pollen particles in its base unit which can be easily cleaned. Also, unlike other air washers, the Air-O-Swiss 2055D has a hygrostat for automatic monitoring of humidity levels. It uses its patented mineral stick for anti- bacterial protection of the water and does not require expensive replacement filters unlike most humidifiers. The Air-O-Swiss air washer is exceptionally fast and is effective in large areas up to 750 sq. ft.