The ZR-3 AFR Gauge works with all Zeitronix Zt-2 and Zt-3 Wideband Systems. The ZR-3 Gauge plugs into the Zt-3/Zt-2 DATA port. Power and serial data is supplied directly through the single connection - there are no additional +12V or ground wires. The ZR-3 cable length is 1.5m.