Cool/Warm Mist Ultrasonic Humidifier. Breakthrough design brings mist closer to user. Ultrasonic technology allows for virtually silent operation, antimicrobial additive prevents microbial growth on the water tank. Oscillating head for broad or targeted mist coverage, easy-fill 1.5 gallon tank capacity with variable output control. Adjustable humidistat for customized room humidity. Suitable for large rooms. Warm mist option prevents room temperature from falling, keeping your room feeling more comfortable.