Compu-Fire 40A 3-Phase Charging System 55575 Provide 25A at idle and 40A continuously above 2800 rpm Unique narrow rotor and stator fit into Softail/Dyna/FLT primary cases as used by most custom builders and the voltage regulator bolts on the stock location 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 Custom-designed flanged seal spacer provides maximum support for the rotor Voltage regulator output is calibrated to 14.25V from idle on up