Changes colors for your mood and promotes restful sleep. Simply add your water and favorite essential oils. 7 bright and 7 dim shades. Large 300 ml (10 oz) tank capacity. Humidifier has an on off switch plus a 60, 180 and 360 timer. Smooth minimalist design. Ultrasonic frequency of 2.4 MHz. Simple plug into the wall style, no need to recharge batteries. Automatic shut off. 12-20 yard coverage. Perfect for aromatic use during yoga or reiki.