Interface that allows you to recalibrate the engine tachometer whatever the number of cylinders or whatever the tone wheel that a tachometer must read and with whichever tachometer and ignition is used, whether the engine is for a car, motorbike or nautical, tractor pulling etc. When the tachometer shows half a quarter or double, triple etc or conditions that require re-calibration, be it a very recent engine or an old one from over 60 years ago, with this module you are able to recalibrate any tachometer!