Shimano xtr di2 m9050 11 speed shifter setfirebolt shifter seamless control instant response with ergonomics based on shimanos rapidfire beginnings the di2 firebolt shifter offers unrivalled intuitive shifting thanks to its shorter lever throw and decreased shift effort shimanos firebolt customizable shift button placement is determined entirely by human ergonomics this means that the shifters are now exactly where your thumbs naturally rest shifts can happen more quickly allowing you