Unifire&reg; Unique Music Design 100ml Aroma Essential Oil Diffuser Ultrasonic Air Humidifier with 4 Timer Settings LED Color Mode with Anti-dry Protection Suitable for Home Yoga Office SPA Bedroom This Aroma diffuser uses Ultrasonic waves to instantly vaporize water and essential oil in the tank, to produce a cool, dry fragrant mist. If you press the MIST switch on main body of the product, mist function is on. You can set up the timer, each time you press down this button, the timer will be changed from 30 minutes, to 60 minutes, to 180 minutes and OFF. When there is no water or few water in the water tank, the power supply will automatic turn off immediately even with power connected. Gently press music touch button at the back of the product, then you will hear special "chirp" "purl", which enables you to feel part of nature. This is perfect for small to medium sized rooms like a bedroom, dining, bathroom or lounge room, especially if they are air conditioned or in winter which makes the air dry.