The energy from the generator is controlled with Field Effect Transistor (FET) technology, which is far superior to mags still using points as a trigger source. FETs are much more accurate, durable and capable of handling much more current This is why the Pro-Mag is capable of delivering full energy sparks throughout the entire rpm range of the engine, while conventional magnetos fall short of full power at high rpm. Plus, the Electronic Points Box keeps each spark glowing for up to 26 degrees of crankshaft rotation. You can plug in an MSD Two or Three Step Module Selector to provide multiple rpm limits that can be used during warm-up laps or for consistent hole shots. Another unique feature of the Pro-Mag 12 is a built-in Soft Touch Rev Control. The rpm limit is adjusted with plug-in modules and will save your expensive engine in the event of driveline failure or missed shift. This system provides a smooth, backfire-free limit. All of the circuits receive a heavy-duty coating of Humi-Seal for protection against vibration and moisture.