AEM Gauge Wideband UEGO Controller AEM"s Gauge-Type Wideband UEGO Controller features an LED readout and sweeping LED needle? That changes colors as AFR changes from rich to lean. The unit is 52mm (2-1/16?) gauge housing fits in most gauge pods and can be remotely mounted virtually anywhere. No laptop required for monitoring! User-programmable 0-5v analog output included for use with data loggers and ANY engine management system. Ideal AFR monitoring tool for carbureted applications and engine dynamometers. Does not oscillate AFR like narrow band sensors