This warm mist humidifier earned The Best rating from the Hammacher Schlemmer Institute because it had the greatest duration of performance, was the easiest to use, and had superior features. In tests, The Best model increased the humidity in a 100' sq. room by 16% in just one hour. It generated constant humidity by providing over 27 hours of operation on a full tank, while lesser units with smaller tanks only lasted 12 hours before requiring a refill. The Best unit was rated as the easiest to use due to its clearly labeled buttons and its top-fill tank that saves one from having to tote a heavy water reservoir. Its list of features include an aromatherapy tray for essential oils, a tank treated to resist mold and mildew, three speed settings, an eight-hour timer, and a nightlight. Includes a cool mist setting. AC plug with 5' cord. 12 1/4" H x 11" W x 8 3/4" D. (4 1/2 lbs.)