Whole house humidifier, manufactured by Trion Corp. Replacement for the 500, 500U, 707TW, 707SM, 707-2 and 707 models. The 356686-001 Centrifugal Atomizer Humidifier was designed with ease of service in mind. Installed on the warm air plenum of a forced air furnace, this model utilizes an electric motor to spray water at a screen and break the water droplets into a steam like mist. Includes discharge extension for optional mounting behind a wall, humidistat and self piercing saddle valve. Operates on 120 Volts AC.