Whole house humidifier, manufactured by Trion Corp. The Model 465-C1 Bypass Humidifier was designed with ease of service in mind. Installed on the warm air or return air plenum of a forced air furnace, this model utilizes an electric motor to spin a filter wheel. Bypass outlet duct can be switched from left to right in the field. Includes a humidistat and self piercing saddle valve. Operates on 24 Volts AC. Bypass flange is 7 round.