Compu-Fire 3-Phase Charging System 55566 40 Amp 3 Phase charging systems provide 25 Amps at idle and 40 Amps continuously above 2800 RPM Unique narrow rotor and stator combination fits Softail and Dyna primary cases Voltage regulator bolts on without any frame modifications Precision balanced vented rotor keeps the stator cooler in closed primary systems to maintain maximum output under all high current draw conditions Large flanged seal spacer provides maximum support for the rotor and the voltage regulator output is calibrated to 14.25 volts from idle on up