Professional Red 2 Oil Pressure Gauge 0 to 80 PSI The Faria Beede Professional Red features perimeter-lighted black dial with stylish Red and White graphics, Black aluminum bezel, tear- drop White pointer, and flat glass lens. A pressure gauge operates by sending a low amperage current through the gauges 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 senders resistance v