General description The 2 in 1 Air Fuel Ratio Gauge Voltmeter is a digital indicator designed for automotive use, providing real-time readings of the air-fuel ratio and voltage. This compact 52mm gauge operates on a 12V system and includes an O2 oxygen sensor for accurate measurements. Technical specifications Working Voltage: DC12V Signal Line Voltage: 0-1V Output Voltage: Maximum value 900mV / Minimum value ≤ 50mV Response time: (600mV-300mV) ≤ 100ms Response time: (300mV-600mV) ≤ 100ms Starting time: ≤ 10s Heating resistance: 8.5-9.5 ohm Internal resistance: 200-300 ohm Color: Black & White Material: Plastic Measurement allowed error: ± 1-3cm Compatibility and accessories Includes: 1 x Air Fuel Ratio Gauge 1 x Cable 1 x O2 Oxygen Sensor 1 x English instruction manual Installation Connect the white line to the heater (no polarity distinction). Connect the black line to the signal line. Connect the gray line to the negative pole of the battery. One white wire connects to the car