Faria Professional Red 2" Water Temp [14604]Professional Red 2" Water Temp (100 to 250 F) Perimeter lighted black dial with stylish Red and White graphics, Black aluminum bezel, tear drop White pointer, and flat glass lens. 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, ect. As the sender's