The Robertshaw 1980-036 Snap-Fit Thermocouple ensures an operative standing pilot light so the main burner gas properly ignites upon a call for heat. Also, it is placed in gas applications to detect a flame and shut off the potential gas flow to a burner. This gas thermocouple has a stainless steel outer jacket for long life and resistance to heat blistering, a combination of copper and nickel alloys for high electrical conductivity, a tinnerman clip and a mica washer to insulate it anst shorting conditions. Various lengths are available for multiple applications. This gas furnace thermocouple easily installs into most pilot burners with an attached threaded nut and it has a brass sheath that provides extra insulation for high ambient temperatures. The lead length is 36" (91cm).