For fast response times, AEM X-Series wideband UEGO air/fuel sensor controller gauges are a great option! Built on the unique, patent-pending X-Digital technology, they report accurate information quickly— enabling you to tune your engine more efficiently. These gauges have modern, visually striking faceplates with 7-segment center displays that are 87 percent larger. They're ultra-slim and come with black bezels and black dual-faced faceplates for air/fuel and Lambda. The displays are user-configurable and feature auto-dimming. 
Additional features: 
* 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 16 V 
* 0-5 V and 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 a percent 
* 52mm gauge diameter and slim 0.825 in. gauge depth 
* Gauge cup depth only .200 in. deep 
* Locking connectors