The Remote Duct Sensor for Venstar thermostats is a digital temperature sensor. Constructed with plenum-rated cable, it is designed to be installed inside the return air duct. A grommet is included to protect the cable from the edge of the sheet metal. This sensor may also be used as a remote room sensor where an unobtrusive sensor is required. When used as remote room sensor, the accessory can be used with the Venstar T1800, T1900, T2700, T2900, T2900SCH and T2300FS thermostats. The sensor will sense room temperature where it is installed. The thermostat will control to the remote temperature sensor and show a blinking degree icon next to the temperature display on thermostat.