MSD
Universal Tach Converter
The output signal that is used to trigger magnetos is different than a conventional electronic ignition. This device converts the Magneto's signal into a 12 volt square wave signal so common tachometers designed for electronic ignitions can be used with poins mags. The converter is less than three inches in length and its circuits are encased in epoxy for water and vibration resistance.
The tach converter is essential when running any EFI system and using a magneto.