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. Shimano EW-SD50 wire for Di2 systems. Key Features: EW-SD50 Di2 electric wire. Fully removable individual cable system from battery indicator junction box that enables fine tuning with the correct length to each component. EW-SD50 wires are required to connect the junction (either SM-JC40 external or SM-JC41 internal) to the rear mech, front mech, battery and to the handlebar battery indicator junction box. Available in varying lengths so there is no need to cut the cables. Secure water resistant connectors.