ULTEGRA RD-RX805 DI2 REAR DERAILLEUR

Shimano Ultegra RX Di2 RD-RX805-GS Shadow RD+ Rear Derailleur - 2x11-speed - medium

The Shimano RD-RX805 rear derailleur features Shimano Shadow RD+ technology and precise accurate shifting, but with the added chain stabilizing switch to control the drivetrain over rough or uneven ground. Much like Shimano's mountain bike derailleurs, the On/Off switch can be found next to the upper pulley. When activated the rear derailleur pivot takes a firm hold to reduce excessive movement, noise and general "chain chatter".
The RX805 rear derailleur is compatible with electronic Di2 road dual control levers and will accommodate an 11-28T cassette up to Shimano's wide-range 11-34T cassette.