TaoTronics Ultrasonic Cool Mist Humidifier emits water mist up to 300mL/h to purify air and improve our respiratory system and skin health. The ultrasonic sound is silent and perfect for home and office use. It's extra fine ceramic cartridge filters water from micro-organisms and bad odor. The filter is easily cleaned and has very low maintenance and prolonged life service. Its classic control knob adjusts work frequency and mist level with a simple twist. Two 360° rotatable nozzles blow mist in two directions at any angle; it automatically shuts off when it detects low water and LED indicator turns red. High 3.5L capacity water tank will last up to 10 hours without a refill. Maximum output of 300±30mL/h produces enough vapor that humidifies the air in a space as large as 150m3 /1600sq. ft.