ESR549 is a high quality regulator/rectifier that replaces the OEM part on various Aprilia models. It has been developed with the newest power circuits inside and thanks to its better heat sink capacity it is far superior to the OEM regulator it replaces. Our use of these modern control circuits offers a stable output power across the RPM range making for a battery that is always fully charged and ready to go. Like all regulator/rectifiers manufactured by ElectroSport this ESR549 also comes with a full one year warranty.