The Points Box controls the spark duration and the unique full power firing sequence of the Pro Mag 12. 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 racing rpm. Plus, the advanced Points Box keeps each spark glowing for up to 26° of crankshaft rotation.Length: 8.4"Width: 4"Height: 2.9"Weight: 3.7lbs