Good original part which was removed from a (never installed) water heater that had exterior damage. Each Combustion Shutoff Device (TRD Thermal Release Device) is identified with a different part number, related to the temperature rating.  IMPORTANT CUSTOMER NOTE: Make sure the part number listed matches the one you are replacing and that the installation is done by a certified professional. These units are made as a one-time safety device and are fully functional. Brands that use this device are Rheem, Ruud, Richmond, and GE.