Auto Meter 4479 Ultra-Lite Electric Air Fuel Ratio Gauge Traditional incandescent lighting illuminates around the perimeter of the dial Gauge kit includes custom tuned .1 AFR Resolution Bosch LSU4.2 Sensor, 8ft. wiring harness, 304 stainless steel weld-in bung, bulb and socket assembly, red and green bulb covers, mounting hardware, and detailed instructions for installation Auto Meters race proven digital stepper motor electric instruments provide unmatched accuracy which is further increased by utilizing a self calibration sequence during power up Display range of 8:1 to 18:1 Suitable for use with gasoline powered engines