Specifications: The thermopile is used with 750 millivolt pilot systems. This system is generally found on gas fireplaces and gas logs that use wall switches or remote controls. This equipment is a kind of cobination type thermocouple, provides power for 250/750 millivolt self-generation control systems. a. Internal resistance (25°C), varies with specifications and length between 1,500 mΩ and 4,500 mΩ. b. Normal working temperature 700-750°C. c. Connecting type: spiral type and two-pole plug-in type. d. Length 36 inch Type: Gas Water Heater Parts Material: copper color:picture color Features: resistance, high temperature resistanceApplicable gas: natural gas / liquefied petroleum gasApplication areas: gas ovens, gas grills, gas boilers, gas , etc. Package Contents: 5 * thermopile Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.