The 14-hour* Ultrasonic Cool Mist Humidifier guards against problems caused by dry air in the home.  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. It is great for tabletops due to its compact size. The humidifier emits a soothing cool mist, and a low water indicator light lets you know when it’s time to refill the water tank. Night light feature makes it a great addition to kids’ rooms.  PureGuardian® humidifiers create a better home environment for those suffering from colds, allergies and dry skin. Note: Run time is based on running the unit on low speed, also depends on atmospheric conditions