300ml water tank design can humidify the air for 4-6 hours Automatic shutdown after 4 hours, press the switch to restart Cool Mist Ultrasonic Humidifier - 30-45ml/hour Cool Mist Ultrasonic Humidifier Compact design with USB power supply Thanks to USB power supply, you can connect it to any USB port device in your home. a compact design that does not take up much space. So it can effectively humidify the air, so that your all-day fatigue is swept away. Quiet operation below 30dB USB powered, easy to carry p> Actual quantity delivered: 1 colored rose