With the twist of a knob, Auto Meter's ''Dial-In-Exactness'' feature allows you to use the tach's pointer to set the chosen shift point rpm for the bright amber Shift-Lite. A switch on the face allows you to check the shift point or recall the highest rpm achieved to aid in tuning. Tachometers work with 4, 6 or 8 cylinder engines with standard, electronic and most high performance/racing ignitions with 12-volt power.