Shimano SLX CS-M7100 Cassette - 12-Speed, 10-51t, Silver/Black, Micro SplinePedal continuously while shifting Lighter and stiffer cassette sprocket construction reduces inertia and increases acceleration 10T lowest sprocket realized by new FREEHUB body construction Advanced shifting performance provides the confidence to enjoy any trail Lighter drivetrain set up Wide range and close step 12 speed drivetrain Cassette Driver Compatibility: Shimano MICRO SPLINE Wide range and close step 12 speed drivetrain Combination: choose;