Cables

Shimano E-Tube wires and connectors - Frame grommets for E-tube internal-wiring compatible frames are sold separately, see Shimano Frame Grommet Kit Electronic Shifter Extra Parts - Ultegra Di2 wires utilize Shimano's e-tube technology; e-tube is a two-prong system and is NOT cross compatible with Dura-Ace 7970 Di2 wiring - All e-tube wires may be used for internal or external applications

Shimano EW-SD300 Di2 eTube Wire for external routing is available in a variety of lengths. - Compact design makes new electric components smaller and lighter - EP8 EP800 Series