Shimano Ultegra Di2 Shadow rear derailleur.

- Sleek integrated appearance
- New low-profile design
- Shimano Shadow RD
- Race endurance
- Optimized slant angle
- Maintain race concentration with more intuitive shift control
- System communication with front derailleur
- Shimano Synchronized Shift
- Wide compatibility
- Short cage covers: 11-25T to 11-30T
- Medium cage covers: 11-28T to 11-34T
- Average Weight: 242 grams (SS type), 249 grams (GS type)