This compact 30-hour ultrasonic humidifier protects against problems caused by dry air in the house. It features an easy to fill 0.8 litre tank, ideal for use on tabletops, for use in small to medium spaces. Unlike other humidifiers that grow slimy mold on the water tank surface, Silver Clean™ Protection is embedded in the tank to combat the growth of mold and mildew on the surface of the water tank. Thanks to ultrasonic technology, it distributes a fine mist into the air, and is ultra-quiet, making it ideal while you sleep. It features an optional aromatherapy tray so a few drops of essential oil can be added to create a relaxing atmosphere. A low water level indicator light lets you know when its time to refill the water tank and automatic shut-off function when the water is too low. PureGuardian® humidifiers create a better home environment for those suffering from colds, allergies and dry skin. Note: The running time is based on the operation of the device on low setting and cold mist, also depends on the atmospheric conditions.