The Shimano XTR SL-M9100 Shifters are the newest generation of XTR. It has the capability of running either 11 or 12-speed drivetrains with a switch that is located on the bottom side of the shifter. Both the left and right shifter feature 35% less shifting force and 20% quicker lever access time than the previous generation. The left-side shifter is completely redesigned and now features one lever to actuate both the upshift and downshift. Simply press the lever in to shift into the large chainring, and then pull the lever back to shift down in to the small chainring. If you're looking for the ultimate in performance shifting, then you'll love the Shimano XTR SL-M9100 Shifters.