2" Water Temperature Gauge 100-200°F - Black Bezel w/Orange Pointer2" - Hole Size: 2.0625" (53mm)A temperature gauge operates by sending a low amperage current through the gauges's meter to ground via a sending unit with variable resistance. The resistance of the sending units increase or decrease with the changes in pressure, temperature, etc...As the sender's resistance varies, the amount of current allowed to flow through it to ground changes and the meter deflects, showing the temperature.100-250 W/NOTCH CASE/BC36. 100-250 Degree Water Temperature Gauge to operate with Standard Resistance Sender. Includes fire orange pointer, tall black aluminum bezel, flat glass lens, case with locator keyway to ensure proper installation and perimeter lighted black dial with stylish white graphics.Available for MG systems, J1939 CAN Bus or J1939 Stand-Alone systems and mechanical types.Benefits:Standard (100-200°F)Black BezelOrange Pointer