Features of the Shimano XT SL-M8100-IL Right I-Spec EV 12-Speed Shifter Light and responsive front shifting improves efficiency, control, and concentration Shift both up and down with a single lever RAPIDFIRE PLUS MONO Instantaneous push and pull movements 2WAY-RELEASE 20% quicker lever access (vs SL-M8000-IL) Customizable ergonomics Adjust to the optimal position for any riding style or rider preference with clean cockpit I-SPEC EV Lightweight and compact design boosts enjoyment on and off the trail