Auto Meter 2091 Prestige Series Black Diamond Tach/Speed Combo Modern white LED through-the-dial lighting provides clear visibility during nighttime use Gauge kit includes mounting hardware, and installation instructions Speedometer is compatible with most two wire sine wave and three wire hall effect vehicle speed sensors. Speedometer can be easily calibrated using the trip reset button on the from of the unit and a premeasured two mile distance. No dip switches! Tachometer is compatible with 0.5 - 6 pulse ignition signals (1-12 cylinder engines) with points, electronic, and most 12V high-performance racing ignitions. Reprogram at any time to accommodate changes in gear ratio or wheel and tire combination with a simple push button, 2 mile drive calibration.