Features Tachometers work by counting pulses generated by the ignition system, alternator, tach signal generator or magnetic pickup sender.; The tach is hooked up to +12VDC.; By selecting the right tach and setting the switch on the back to the correct position you let the tachometer know how many pulses are sent per each engine revolution.; Check Engine.; Temperature & Oil Level.; Rev & Limit.; Item Weight - 0.70 lbs.;.
