ESR547 is a high quality regulator/rectifier that replaces the OEM regulator on Triumph 2-Cylinder models. Our ESR547 offers superior performance by utilizing our latest generation power circuit which is installed in a highly efficient heat sink. ESR547 offers a super stable battery voltage across the RPM range and will run much cooler than the OEM unit due to the improved heat sink design. All in all: this is a great improvement over the stock Triumph regulator/rectifier. ElectroSport supplies ESR547 with a full one year warranty.