1. [Clear and Accurate Reading] Air Fuel Ratio gauge features bright LED backlit display ensuring clear visibility even in the darkness. Designed with meticulous precision, it provides quick, reliable results, enabling you to keep a close eye on your car's health and performance. 2. [Best Size and Range] This 2-1/16inch(52mm) Air/Fuel gauge with its sleek black dial provides accurate Air/Fuel ratio readings ranging from 10.00 to 20.00 AFR.It's compact yet readable size allows for easy installation and use in your 12V vehicle. 3. [Universal Applicability] Designed for seamless compatibility with 12V cars, offering Best performance and easy operation. This Air/fuel ratio gauge will provide you with the essential vehicle statistics you need while being speedy and simple to install. Placement on Vehicle:Air Fuel Ratio Interchange Part Number:Narrowband O2 Oxygen Sensor Special Features:Car Gauge Item Weight:400g Manufacturer Part Number:2 Inch Gauges Part Number:AFR Meter 52MM Colour:Black Material:Plastic Size:Item Height:52mm, Item Width:52mm, Item Length:52mm Package Contents: 1 * Air Fuel AFR Gauge 1 * English Manual(Only teach how to install the gauge,but do not teach how to install the O2 sensor,thanks) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.