Shimano SLX FC-M7120-1 Crankset - 170mm 12-Speed Direct Mount Hollowtech II Spindle Interface BLKShimano SLX FC M7120 1 Crankset 170mm 12 Speed Direct Mount Hollowtech II Spindle Interface Black. The Shimano SLX FC M7120 crankset for MTB features a rigid and lightweight design that boosts trail riding enjoyment. The simplicity of a 1x drivetrain with the stability and compatibility of Hollowtech II technology. 1x Chainring sold separately Hollow forged crank maximizes power transfer while limiting weight Shimanos Hollowtech II technology provides