Car Air Fuel Ratio Gauge 12V Racing Air Fuel Meter Indicator with Narrow O2 Oxygen Sensor 0258006028 52MM Gauge Pod CUpType:2.Air Fuel Ratio (10~20)Specification:Color:Black Voltage:DC 12V Diameter:52mm/2 Material:Plastic Quantity: 1 Set Fitment: for Gasoline car 12V ,not for any other motor, truck or boat vehicle etcConnection:Connection : The white line is at heater ab Black line signal line C, gray line signal ground D The 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 switch The white line is the heater and does not distinguish between positive and negative electrodes About the air fuel gauge, please see the installation instructions.Package:1 x gauge or 1x sensor or 1x gauge and sensor