The Maxitrol TS114F Discharge Air Sensor is a device used in HVAC systems to monitor the temperature of air leaving the furnace or heating element. It screws directly onto the ductwork using a standard 1-inch NPT fitting. The sensor then sends this temperature data to the HVAC control system. https://www.partshnc.com/ts114f-maxitrol-discharge-air-sensor-40-80f