Auto Meter 4393 Ultra-Lite Fuel Rail Pressure Gauge Traditional incandescent lighting illuminates around the perimeter of the dial Gauge kit includes wiring harness, bulb and socket assembly, red and green bulb covers, mounting hardware, and detailed instructions for installation Included wire harness connects to original equipment fuel rail pressure sensor wiring Auto Meters race proven digital stepper motor electric instruments provide unmatched accuracy while keeping hazardous fluids outside of the vehicle The accuracy of digital stepper motor gauges is further increased by utilizing a self calibration sequence during power up