Reliable and proven Di2 technology makes it way to Ultegra for incredibly easy and very precise shifting. Di2 shifters send a signal through wires to small motors built into the derailleurs so there is no straining to pull a cable or relying on spring tension. All the buttons are in the same location as the standard STI levers so the learning curve is virtually nonexistent. The buttons require a light touch and only 2mm of movement for perfect shifts every time. Di2 shifters are as soft as perhaps a mouse click and can be a huge benefit for anyone with hand issues like arthritis or carpal tunnel.

Because the levers don't need to house any shifting mechanism due to the Di2 design they can be made as light and ergonomic as possible. They have a reach adjustment to fit all hand sizes. The Di2 6770 STI levers are, in fact, about 135 grams lighter than the 6700 levers. The levers are more sleek with a lower profile and have improved ergonomics designed to enhance long-distance comfort. Shifting can be done while coasting with the derailleur executing the shifts when pedaling resumes.

The Ultegra Di2 STI levers are one part of the Di2 system including shifters, derailleurs, battery, battery charger, and several cables/wires.

Used for three seasons on my wife's main bicycle, just upgraded her to hydraulic so these must go.

Light scratches here and there but are fully functional. These have been used in an 11 speed setup but will work with 10 speed derailleurs.