Material: metal. Package Contents:1X Thermocouple. REPLACEMENT FIREPLACE THERMOPILE-compatible with the majority of units. For example water heater, Oven, Fireplace & Stove etc. & ENERGY SAVINGS-Lengths: 36 inches. Wire Material: glass fiber wrapping line, metal aluminum envelope, these two lines are high temperature resistance fire line, you can choose according to their own needs, focus on length. Our parts are designed and tested for exact equipment specifications, so they work more efficiently and can result in energy savings over time. EASY INSTALLATION-Spiral type and two-pole plug-in type, Installs quickly and easily tool-less attachment to propane tan. Only the above package content, other products are not included. Note: Light reflection 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.