ESR819 is a heavy duty and very high quality Regulator/Rectifier that replaces the Polaris OEM regulator. ElectroSport incorporated the latest electronic regulation circuitry and built the ESR819 into a highly efficient heatsink that is dimensionally identical to the OEM unit. After installation of the ESR819 you will notice a stable voltage across the RPM range perfectly matched to what your battery needs to see as a charge rate. The unit comes with the same wiring and connectors as the OEM regulator and this ESR819 is therefore a true plug-in replacement. Like all Regulator/Rectifiers manufactured by ElectroSport this ESR819 also comes with a full one year warranty.