105 Shadow design with Di2 technology, shifting is easy and precise - just a light touch, as soft as a mouse click, is sufficient for the front or rear derailleur to instantaneously select the correct gear

Features

• The rear derailleur is now the brains of the system with wireless connectivity to the shifters. It acts as the point the system is charged, provides ANT+ connection to 3rd party devises and replaces the handlebar junction
• Button on the derailleur for Di2 operations, and LED light denotes synchronized shift mode, setting mode and charge requirements
• Sleek appearance with Low profile Shadow design construction reduces risk of damage in a crash
• Programmed automatic motion at the touch of a switch makes this derailleur quick, smooth and effortless to shift
• The removal of traditional mechanical cables in favour of electrical wires to the battery not only eliminates poor shifting caused by contaminates, corrosion and stretching, but provides effortless gear shifts
• Derailleur contains a saver (fuse) function, where the inner structure is protected from strong impacts
• High tolerance cold forged aluminium link plates and body construction is extremely light and durable
• Four self-lubricating micro-machined fluorine-coated link pivot bushings provide low-friction shifting
• 12-speed E-tube Di2 compatible
• Wide gear ratio compatible up to 11-36T