Usage Tips:Feature:- High Precision- Racing look enhance the characteristic to your car or vehicle- Fitment : Universal 52mm diameter Voltmeter fit for Motorcycle Car or Truck or Gasoline Engine(The compatibility just for reference .Please make sure the item fit for your car before purchase.)Fitment:Fit most of 12Volt gasoline vehicle,Fit 2" or 52mm Diameter Gauge Pods holderApplication:Color:BlackVoltage:DC 12VDiameter:52mm or 2Material:PlasticQuantity: 1 SetConnection:The white line is at heater abBlack line signal line C, gray line signal ground DThe green wire of the instrument is connected with the black wire of the sensor. The gray line is connected to the negative pole of the battery.One white wire connect with the car shell or battery negative pole.Another white wire connect to the ACC line of ignition switchThe white line is the heater and does not distinguish between positive and negative electrodesAbout the air fuel gauge, please see the installation instructions.Please select the correct SKU when purchasing, as shown in the picture for the package's productPackage Included: as the picture shows1x Air Fuel Ratio GaugePackage Included: as the picture shows1x Air Fuel Ratio Gauge1x SensorPackage Included: as the picture shows1x SensorOR1x Gauge Cup