Fangrui Product Details 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 Units 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.