Rear derailleur Shimano DURA-ACE Di2 RD-R9250 SH+ 2x12-speed

Faster than ever before. The RD-R9250 model not only offers the fastest gear changes on the cassette to date and the largest gear ratio range of a Dura Ace rear derailleur, but can do much more. By integrating the Wireless system and charging port into one compact unit and thus covering a wide range of functions, it practically becomes the heart and brain of the entire Di2 assembly. The built-in transmitter ensures wireless co mmunication with the STI brake/shift levers ensuring podium-worthy, lightning-fast and precise shifting. Using Bluetooth and ANT+, it is also responsible for data transmission to the E-Tube Project and E-Tube Ride apps as well as to third-party devices. Besides the charging port, the Top Normal rear derailleur features a button for certain Di2 settings and an LED for status display informing you about battery level, pairing and setting mode, for example.