ESR279 is a high quality replacement regulator/rectifier for various Yamaha models. The OEM unit is tiny compared to the power it needs to handle and this makes this OEM regulator run extremely hot. For most of its applications we could not alter the physical size of this regulator to allow for better heat sinking. Therefore we incorporated our newest generation of regulation circuits which runs much cooler than the OEM version. The voltage output of this regulator/rectifier is super stable across the RPM range so the charge rate of the battery is always correct. We offer this ESR279 regulator/rectifier with a full one year warranty.