The SRAM AXS extension cord is an optional item to the Eagle AXS system to power the derailleur by the main system battery instead of a separate AXS battery. The extension cord interfaces to the derailleurs AXS battery port and is designed to be internally routed through the frame directly to the e-bike motor/battery. The extension cord is available in different length to accommodate frame sizes and design. Works with any AXS derailleur Powers derailleur by main system battery Compatible with Bosch Smart Systems