Cool Mist helps restore moisture to dry indoor air. Helps to relieve cold & flu symptoms. New cyclone technology creates a fine mist. Healthful and convenient fillchannel for easy filling quiet operation. Up to 20 hours of operation per filling, 1.2 gallon capacity (4.5 liters). Air cleaning filter helps remove pollen, dust, odors and tobacco smoke. 2 year warranty. How it works: The motor-driven impeller draws water up through its pickup tube, then propels the water by centrifugal force against the screen to provide a fine vapor, which is then whirled through the Cyclone Misting Chamber to provide a fine vapor, which is then whirled through the Cyclone Misting Chamber to provide a superfine mist. At the same time the exclusive Protec DynaFilter Air Cleaning Filter helps remove dust, pollen, odors, and tobacco smoke from the room air, removing 93% of particles as small as pollen. The model 4100 humidifier also features the exclusive Kaz Water FillChannel. Visible superfine mist output. Helps you breathe better and sleep more comfortably. Replaceable air cleaning filter helps remove pollen, dust, odors and smoke. Water FillChannel permits filling without removing motor housing. Dispenses a pure, visible vapor.