This Auto Meter 4375 Ultra-Lite Electric AFR Air Fuel Ratio Gauge Narrowband O2 52mm is a must-have for any racing enthusiast. It is designed to help you monitor the air-fuel ratio in your engine, ensuring optimal performance. The gauge is made by Auto Meter, a trusted brand in the industry, and comes in a sleek white color. Item cant be tested and for that reason is being sold as is. Please be mindful of this before purchasing.