FEATURES: X-Series Wideband UEGO AFR Controller Gauge were fastest responding wideband air/fuel ratio controllers in an independent test vs. 17 competitor wideband AFR controllers Includes Bosch 4.9LSU wideband UEGO sensor Factory calibrated resistor does not require free-air calibration, but technology allows for free-air calibration as sensor ages if user desires Compatible with vehicle/system voltages up to 16V 0-5V & RS232 output for data logging and feedback control, AEMnet (CANbus) for data logging and daisy-chaining multiple controllers up to 16 cylinders Can display AFR values in hundredths of % 52mm gauge diameter and slim 0.825 gauge depth Gauge cup depth only .200 deep! Auto dimming feature User configurable display via buttons on the gauge face for changing AFR values, Lambda and O2%, and 3- or 4-digit display Black bezel and black dual faced faceplate included (gauge only, silver bezel/white gauge option sold separately, PN 30-0300-ACC) Locking connectors