Product Description: Notes: Tap water is the best choice. If the water added over max line, the mist will be very thin(less water, more mist) Please don't touch the internal ultrasonic wave vibration board inside of the water tank directly with your hands. If the ultrasonic wave chip was polluted, it may cause error action or default. Tip: oil is not included in the package Description: Looking for a simple way to calm and freshen a room? The urpower ultrasonic aroma essential oil diffuser is elegant and easy to use. Just add 100ml of water and a few drops of your favorite essential oil. Advanced ultrasonic vaporizing diffusion technology quietly releases a soothing fragrant mist up to 6 hours. Automatic shut off safety system when waterless protects the product from being burned out. Keep essential oil 100% natural without burning or heating and automatic shut off safely. The humidifier function adds moisture to the air to help you sleep better, cough less and alleviate dry sinuses. This handy unit also diffuses your favorite scented oils without heat, so their holistic properties stay intact. The result is healthful, moist air that smells subtly fresh and clean. Features: Size: 5.5"(H) x3.1"(W) Material: upper parts pp Input power: ac100-240v 50/60 Hz Advanced ultrasonic technology: 2.4 MHz Length of the power supply cable: about 69.6 Inch. No filters required, works with ordinary tap water Auto shutoff for safety, whisper-quiet operation Package includes: 1 x ultrasonic aroma essential oil diffuser 1 x charger adaptor 1 x measuring cup 1 x user manual.