Compatibility: Shimano 105 R7150/R7170 Compatibility: Shimano Ultegra R8150/R8170 Compatibility: Shimano Dura-Ace R9150/R9170 Reduced Size: Lighter and Smaller Electric Components Potential Future Expansion: DI2 System Capabilities Usage: Internal Routing This Shimano EW-SD300 Di2 12 Speed eTube Wire is compatible with Shimano's 12-speed Di2 systems, including 105 R7150/R7170, Ultegra R8150/R8170, and Dura-Ace R9150/R9170. Its compact design reduces the size and weight of new electric components, and it could potentially enhance the future capabilities of Di2 systems.