AFTERMARKET RPM CYLINDER REV COUNTER TACHOMETER FOR SPORT CAR & TRUCK WITH SHIFT LIGHT : MECHANICAL, ELECTRONIC

A tachometer (revolution-counter, tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analog dial, but digital displays are also common nowadays. While driving，the tachometer can ensure that we are shifting at the appropriate time to prevent unnecessary transmission wear.