Crane USA Travel Cool Mist Humidifier, Grey ULTRASONIC COOL MIST: Increases air moisture for easier breathing and a good nights sleep ACCESSORIES INCLUDED: Includes carrying bag, portable tank, and power adaptor that works with power outlets or any USB port 10 HOURS OF RELIEF: Runs whisper quiet for 10 hours, from any standard size cup AUTO-OFF SENSOR: Activates when water tank is empty CLEAN CONTROL: Antimicrobial Material is proven to help reduce mold and bacteria growth up to 99.96% VOLTAGE  120 V, for domestic use only