The AEM Wideband X - Series UEGO AFR Gauge has a user configurable display via buttons on the gauge face that allows you to change AFR values for different fuels, Lambda or O2, change the center display to three or four digits, perform a free - air calibration if desired as the sensor ages, and change the CAN message ID when linking multiple X - Series Inline Controllers or X - Series Controller Gauges. A black bezel and black dual - faced faceplate for airfuel and Lambda are included, and an optional silver bezel with white dual - faced airfuel and Lambda faceplate is available (PN 30 - 0300 - ACC, sold separately). An Auto Dimming feature is included. Locking connectors ensure a positive connection between the harnesses and gauge and a new single board design adds to the new gauge's durability.