ESR684 is a high quality regulator/rectifier that replaces the OEM regulator on the CBR1100XX Blackbird models. We incorporated our latest generation power circuit inside our very efficient heat sink design resulting in our ESR684 which is superior to the OEM unit on these Blackbirds. Our ESR684 offers a completely stable voltage output which means your battery will get the optimum charge for your battery at any engine RPM. And thanks to our advanced circuit and heat sink this regulator runs much cooler than the stock unit. ESR684 is a Plug-In replacement regulator/rectifier that comes with a full one year warranty.