Silent ultrasound. The humidifier runs very quietly at less than 45 dB. Never let yourself be disturbed by bubbles and engine noise. You can enjoy a quiet time while sleeping, working or driving. Stay healthy: humidifier provides cool mist to eliminate static electricity and dust in the air. Suitable humidity helps relieve nervous tension, eliminate fatigue, penetrates the underlying skin quickly, soothes dry skin and eyes. Adjustable mist and LED. You can easily switch between the mist modes and LED fades, continuous spraying and intermittent spray, gradual colour change or single colour of LEDs to create a warm and romantic atmosphere. Wide usage: Ideal for different environments, don't worry about your baby's sleep quality when you are in the dark. It can also serve as a desktop decoration to create a cosy and pleasant atmosphere. USB powered: the humidifier can be powered by a USB cable. No adapter included, USB cable included, can be used with computer interface, laptop, power bank. 320ML Mini Ultrasonic Humidifier: USB humidifiers can be used with the power bank of a computer or other USB power supply. Environmentally friendly ABS (acrylonitrile butadiene styrene) + PP (polypropylene) + silicone material, safe and durable, provides long-term use. Very quiet, less than 40 dB during operation, does not affect your child's sleep or families. Great gifts, elegant design is a good choice for gifts. Ideal for birthday, Christmas, etc. 3 steps to install: Unlock the cover cap counterclockwise. Fill water into the water tank. Rotate clockwise and tighten the cover. Click button and enjoy. How can the cotton swab be replaced? Pull out the cotton swab and then replace the cotton swab. Please pay attention to the lower spring when replacing. Technical data: Noise level: 36-45 dB Material: ABS + PP + Silicone Plug format: USB Water tank: 320 ml Size: 16.5 x 7.2 x 7.2 cm Weight: 242g Input voltage: DC 5 V Working current: 400 mA Rated power: 2 W Time of use: 6 - 12 hours Package included: 1 x ultrasonic humidifier with 4 filter elements 1 x micro USB cable 1 x user manual [cannot guarantee English language] 4 x cotton buds Note: Allow to use processed water. Do not use with aroma or essential oils in the water tank. Normal humidifier is not corrosion resistant.