This is a Shimano Ultegra Di2 EW-SD50 Extension Wire for all Di2 systems except Shimano 7970 Dura-Ace. All e-tube wires may be used for internal or external applications Frame grommets for E-tube internal-wiring compatible frames are sold separately
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