The 100-hour PureGuardian Ultrasonic Cool Mist Humidifier Tower enhances comfort, helping you sleep better. It provides quick relief from dry air making life pleasant for those with colds, allergies and dry skin. The space-saving tower design, with an easy-to-fill large 1.5 gallon tank, is ideal for use in medium size rooms. Unlike other humidifiers that grow slimy mold on the water tank surface, Silver Clean Protection is embedded in the tank to fight the growth of mold and mildew on the surface of the water tank. Thanks to ultrasonic technology, it disperses a fine mist into the air, and is ultra-quiet making it ideal to have on while you sleep. This tower humidifier has an optional aromatherapy tray so a few drops of essential oil can be added to create a relaxing atmosphere. The humidifier is equipped with a 12-hour timer, a night light and variable mist control. An indicator light lets you know when it’s time to refill the water tank. The humidifier shuts off automatically once empty. Note: Run time is based off of running the unit on low speed, also depends on atmospheric conditions. Quick Relief From Dry Air with Ultrasonic Technology that Immediately Disperses Mist Higher into the Air Enhance Comfort and Sleep Better with Soothing Cool Mist, While Making Life Pleasant for Those with Colds, Allergies and Dry Skin Fights the Growth of Mold and Mildew on the Surface of the Water Tank with Silver Clean Protection Up to 100* Hours of Run Time is Provided with a Large 1.5 gallon tank that is Ideal for Medium-Sized Rooms Aromatherapy Tray option helps create a relaxing environment with your favorite essential oil. Oils not included.