A wideband UEGO sensor controller accurately monitors Air/Fuel ratios (AFR) during the tuning process to prevent a lean fuel mixture, which could lead to engine damage. It has combined its single-channel wideband UEGO controller and gauge display into one unit, uniting unsurpassed AFR accuracy and control with an easy-to-read interface. The Gauge-Type Wideband UEGO Controller features a digital LED display and sweeping LED inch needle inch that changes colors as AFR changes from rich to lean. The unit's 52mm (2-1/16 inch ) gauge housing fits in most gauge pods and can be remotely mounted virtually anywhere. Part Number:30-0300 Colour:Black Material:plastic Package Contents: 1 x O2 Air Fuel Ratio Gauge Kit 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.