This device is a portable mini ultrasonic air humidifier and essential oil diffuser. 
Key Features Design: Compact, cup-sized design optimized to fit seamlessly into car cup holders or on small office desks. 
Functionality: Uses ultrasonic vibration technology to break water into a ultra-fine cool mist. up to the maximum fill line. 
Optional: Add 1 to 2 drops of water-soluble essential oil if you wish to use it as an aroma diffuser 
Power On: Seal the top back onto the base securely, plug in the USB power cable, and press the main power button once to start the continuous mist mode