Shimano Ultegra Di2 RX805 11 Speed Rear Derailleur Tackle the paths less travelled with the Shimano Ultegra RX R805 11-Speed Di2 Shadow+ Rear Derailleur. Being the GS variant, this versatile derailleur is compatible with cassettes with a minimum sprocket of 11T and a maximum of 34T; perfect for undulating alpine routes. Removing the need for mechanical cables, this Di2 option eliminates poor performance caused by contaminates, corrosion or stretching, while the saver function protects the inner structure from large impacts. The high tolerance cold forged aluminium construction is both lightweight and durable, while the low profile Shadow plus design tucks the derailleur out of harms way. Completed with an RX clutch, the RX 805 reduces chain chatter and effectively maintains tension, no matter the terrain below. This intuitive feature makes this a perfect choice for gravel riders and cyclocross racers alike.