This compact and easy to install module will allow you to easily adapt AutoMeter tachometers and shift lights and many other aftermarket RPM-based devices on your alternator-equipped diesel or non-standard ignition gasoline engine. Equipped with a sensor which is mounted to the alternator casing, a one time setup calibration is accomplished via push button interface on the module to synchronize the alternator signal with engine crank RPM. Perfect for diesel performance applications looking to add a tachometer or upgrade from factory equipment and a great problem solver for engine swap builds in need of working instruments. Pair it with AutoMeter's low-rev tachometer models to complete your diesel-specific gauge installation.