Compu-fire 40 Amp Charging System for Big Twin Authorized US Dealer/ Made In USA!. Great Charging system an will ship from my location in Southern Illinois. Compu-fire is well known for making top notch ignition and charging products so you can purchase with confidence. Replace your old charging system or do a complete upgrade while doing some work. .Weight: 9.77 3 phase type system produces 25 amps at idle and 40 amps above 2800 RPM. This amount of amperage provides a constant DC voltage of 14.25 from idle on up Precision balanced rotor is vented to create better oil flow to the stator that helps to reduce the temperature by 50° Large flange of the seal spacer provides additional support to the rotor without the use of a separate washer Series-type regulator/rectifier is designed to reduce unnecessary drag on the engine by unloading the stator whenever the battery reaches full charge Provides the off-idle power required for fuel injected models Compu-Fire Fits Big Twin 1970/1999 (except Twin Cam) with closed primary (oil bath type)Note: 1970/1975 models will require a 2 bolt type regulator/rectifier mount & 1970/1981 models may require slight clearancing of the primary covers