The Glip Waterdrop KX-6690 Humidifier improves air quality and alleviate symptoms of dry air such as dry skin sneezing coughing and sinus. The ultrasonic humidifier atomized water into ultra-fine particles of 1-5 um using the principle of ultrasonic high-frequency oscillation and diffuses the water fog into the air through a pneumatic device to serve the purpose of even air humidifying. Thanks to ultrasonic technology the humidifier operates very quietly and no filter needed. It has a duration of up to 12 hours with 2.3 gallon of mist output and suitable for room size of 250 square feet. Improves air quality and alleviate symptoms of dry air such as dry skin sneezing coughing and sinus No filter needed Ultra quiet operation Auto shut-off when water tank is empty Runs up to 12 hours 0.6 gallon water tank with up to 2.3 gallon of mist output Suitable for room size of 250 square feet.