Ultrasonic humidifier disperses visible cool mist from a dual-direction outlet to help soothe irritation from dry air 1-gallon water tank is ideal for medium-size rooms and provides up to 36 hours of operation per fill Wide tank opening and included cleaning brush let you fill and clean the tank with ease Control dial with variable moisture output allows you to customise the comfort level of your space Auto shut-off function turns the humidifier off when the water tank is empty Built-in essential oil tray makes it easy to diffuse your favourite fragrances