Shimano Ultegra Di2 6770 STI Shifter - Left 2 SpeedShimano Ultegra Di2 6770 STI Shifter Left 2 Speed The Shimano Ultegra Di2 6770 STI Shifter is specifically designed for road use as it gives you quick and reliable gear changes with Di2 electronic shifting. Ready for racing, this STI shifter features a dual control lever for double cranksets and allows you to enjoy fast and smooth gear changes. Coming equipped with an effortless electronic push button shifting mechanism, this model gives you flawless