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 gauge'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 change in pressure. 2' - Hole size: 2.0625' (53mm) Specifications: * Flat Scratch Resistant Lens * Black Aluminum Bezel * LED Illuminating around the Perimeter of the Dial * Tear Drop White Pointer Factory P/N GP7063 *Sold as an Individual **Gauge Cover not Included