The Serenity Diffuser is an elegant, exotic way to enjoy the natural benefits of essential oils. It's sleek, quiet, ultrasonic design fills your room with an ultrafine vapor which will allow for our essential oils to be suspended in the air for longer periods of time and for better inhalation. This process does not heat essential oils, keeping their holistic properties intact. The Serenity uses tap water as well to keep things simple. It features a small blue nightlight on the bottom of the unit which can also be turned off.