Electrical oil temperature gauges indicate engine oil temperature in degrees Celsius (°C). A matching ETB temperature sensor is required to provide the gauge with the correct input resistance. The gauges are supplied a 'U'-shaped fixing bracket and thumb nuts along with a 12v /2w illumination bulb. Night illumination is classic white.
The gauge size of 52mm denotes the outer diameter of the main body of the instrument and hence a 53mm to 54mm diameter hole is required in the dashboard.
Wiring diagram here.