Shimano EW-RS910 Junction Box A

The Shimano EW-RS910 Junction Box A serves as a vital connector in the E-tube wiring system, linking to key points on the bicycle such as the front derailleur, rear derailleur, cockpit junction box, and battery mount via SD50 E-tube wires. It's crucial to note that all Di2 components on the bike must share the same firmware version to prevent malfunctions.