Ultrasonic Operation and Ultra-silence Design:Mini usb humidifier adopted ultrasonic technology,whisper quiet,humidifiers for bedroom,you can breathe easy and get more restful sleep high.Humidify your living space to prevent dry, stuffy air and flu/cold germs infecting your loved ones. Prevent dry and chapped skin in dry seasons with no noise.^Auto Shutdown Technology:4 hours automatic power-off protection,Auto shut-off when water tank is low to protect the humidifier is motor and increase durability and safety.Make sure there is enough water before running.Small humidifier,you can connect computers,laptops,portable chargers and other devices with USB output.^Cute cactus shape and vibrant color will bring happiness to your room, desk, office, car and travel.Portable size was easy to take anywhere.It will be a fabulous Christmas or birthday gift for your relatives, friends and colleagues.^MaterialAbs, Silicone^Capacity160 Milliliters^