The Shimano Di2 SM-JC40 Junction Unit for External Cables is the Grand Central Station of the e-tube Di2 system.

Dura-Ace Di2 (Dual Integrated Intelligence) moves to the next generation. Tested in competition and taken to victory by pro riders in all conditions, including the 2012 Tour de France Team Sky.

Features

• SM-JC40 cable junction for external wire routing
• Junction is required for connection of rear mech, front mech, battery, and cable to battery indicator junction box
• To be mounted on bottom bracket cable guide threaded fitment
• Reliable and secure water resistant connectors
• Compatible with Shimano e-tube Di2 systems

Junction box for Shimano Di2 wire EW-SD50 with external routing. The junction box is for mounting under the bottom bracket. Front/rear derailleur, cockpit area and battery are connected here.

Note: Only compatible with Dura Ace 9070, Ultegra 6770, XT 8050, Alfine Di2 und Nexus Di2. Not compatible with Dura Ace 7970 Di2.