The 10-hour Ultrasonic Cool Mist Humidifier guards against problems caused by dry air in the home. Cleanliness matters!Thanks to ultrasonic technology, it disperses a soothing, cool mist into the air. It is great for tabletops due to its compact size. A low water indicator light lets you know when it's time to refill the water tank and the night light feature makes it a great addition to kids' rooms!  PureGuardian humidifiers create a better home environment for those suffering from and dry skin. It is important to only use GENUINE Guardian Technologies replacement parts to maintain product performance.