300ml water tank design can moisturize the air for 4-6 hours Automatic STOP after 4 hours and press the switch to restart Ultrasonic cool mist for humidification - 30-45ml/hour Quiet operation below 30 dB USB powered, convenient for carrying Why do we need a humidifier? A humidifier can help remove dryness from the air. With the moist air around, it can help relieve dry skin, refresh the breathing air, improve the sleeping environment, and thus provide a healthier life. Why do we need humidifiers 300ml water tank design can moisturize the air for up to 4-6 hours Automatic STOP after 4 hours and press the switch to restart Ultrasonic cool mist for humidification - 30-45ml/hour Quiet operation at less than 30 dB USB powered, convenient to carry Offers a soothing 7-color nightlight for maximum relaxation