Key Features:Dyna-Sys11 11-speed shifter with Vivid indexing and Multi and 2-Way release to exceed the demands of ever changing bicycle designs and riding styles,Light to the touch but positive and crisp, Vivid indexing gives a constant amount of shift lever force across all 11 sprockets,2-Way release: the upper lever still performs the same shift function, but it can now swing in either direction allowing it to be released by the thumb or index finger,Multi Release allows multiple gear changes with one sweep, further adding to the speed of shift,Multi-bearing design uses two ball bearing units to give a low-friction and reliable shifting action,One piece lower alloy thumb release lever with anti-slip increases durability and gives sharp precise shifts,For use with Dyna-Sys11 11-speed only,Raised optical gear display instantly shows you what gear you're in and allows clearance for suspension lock out clamps below,I-spec-B design is developed to attach directly to I-spec-B brake levers.