These AutoMeter ES Series wideband air/fuel gauges will help you tune and monitor your engine's air/fuel ratio. They include an 8 ft. wiring harness and a high-quality Bosch wideband oxygen sensor. The auto-dimming feature allows you to adjust the brightness of the gauge display. The AutoMeter ES Series wideband air/fuel gauges can display a Lambda (bar graph) or LED digital numeric air/fuel ratio, have peak recall, and use a 0-4 V data output feed for ECU, data acquisition unit, or laptop tuning. Adjustable for alternate fuel types such as ethanol, methanol, or propane, the AutoMeter ES Series wideband air/fuel gauges will help keep your engine operating efficiently under all conditions.