Features large LED back lighted dial, fog-resistant polycarbonate lens and plug and play connectorized cases. The stepper motor driven pointer provides accurate feedback of information reported by the engine ECU. 4" gauges use a 3.375" hole, 2" gauges use a 2.0625" diameter hole. GEO166, GEO167, GEO168 connect directly to the MG3000 Tachometer. Digital signals are processed by the engine and sent through the tachometer providing an easy to use display of the information.