ESR125 is a high quality and better-than-OEM regulator/rectifier for your Honda TRX300. We built our ESR125 using the latest technology in regulator circuitry, and use a very efficient heat sink to get rid of the heat quickly and efficiently. ESR125 controls the output voltage very accurately resulting in a perfect charge rate for your battery across the RPM range. Just as with all other regulator/rectifiers manufactured by ElectroSport our ESR125 comes with a full one year warranty.