The thermocouple sensor with safety dump switch replacement Kit fits most gas/propane heaters, patio heater, and thermoelectric gas heaters Weak current FD4 Dump safety switch is for gas R≤10 mΩ and universal thermocouple wire total 23.5 inches(600mm). thread M8 x 1 Ends Easy To Install&Use.The probe is connected to the ignition device, the thermocouple is connected to the valve, and the other two ports are connected to the safety dumping switch, which does not require special tools and is fully compatible with the original components Usually the service life of a Thermoelectric Safety Device: ≥10000 times, If your heater cannot lit and the thermocouple does not work, it will be necessary to replace this part， which can prevent the occurrence of gas leakage when the fire is extinguished and the gas is still on, which is more secure The safety dump switch thermocouple sensor by CSA certificate, and the head of the thermocouple is not threaded, Check that it is suitable for your heater before purchasing the product Propane Gas Patio Heater Repair Replacement Accessories Thermocouple and Anti Tilt Switch Kit,Fits for Patio and Room Heater Garden Outdoor Heater.