Specifications: The thermopile is used with 750 millivolt pilot . This formulation is generally discovered on fuel fireplaces and gas logs that use wall switches or remote controls. This package is a kind of cobination form thermocouple, provides strength for 250/750 millivolt self-generation leadership . a. Internal resistance (25°C), varies with specifications and size between 1,500 mΩ and 4,500 mΩ. b. Normal operating temperature 700-750°C. c. Connecting type: spiral variety and two-pole plug-in type. d. Length 36 inch Type: Gas Water Heater Parts Material: copper color:picture colour Features: corrosion resistance, hot temperature resistanceApplicable gas: pure fuel / liquefied petroleum gasApplication areas: gas ovens, gasoline grills, gasoline boilers, gas , etc. Package Contents: 5 * thermopile Only the above equipment content, various item should not included. Note: Light and various exhibits could cause the colour of the thing in the photo a little bit various from the real thing. The size allowed error is +/- 1-3cm.