Connect to oxygen sensor and determine whether the engine is running rich or lean for maximum performance efficiencyDual display offers independent or dual left/right bank vs. inline readingsColor LEDs provide a quick visual display of air/fuel ratioAluminum bezel is lightweight and optimizes appearanceRear twist-on ring mount design makes mounting simpleThis air/ fuel gauge features a dual display that offers independent or dual left/right bank vs. inline readings. It includes electrical connectors for installation on most vehicles – foreign and domestic