Ultrasonic Sound: The air humidifier uses ultrasonic and noiseless design to purify the air, improve sleep quality and ensure peace of mind. Less than 30 dB, a calm atmosphere can create a pleasant sleeping environment. Automatic shutdown without water: This air humidifier will shut down automatically when the air humidifier is out of water, it is very safe and durable. The large cool spray can produce 360 ​​° fog to ensure a cozy atmosphere from all sides. Portable and 2 spray modes: The mini air humidifier is 8 x 8 x 16 cm in size, easy to carry and place. The air humidifier can be placed on the table, in the car, in the room and in the office. The air humidifier can run for 8 hours in spray mode or 20 hours in intermittent spray to enjoy a cool mist. USB Air Humidifier: The air humidifier works with a USB charging cable. This air humidifier can create cool mist and remove static electricity and dust in the air. In dry winter, an air humidifier can improve dryness and chapped skin.