Product Info Wide range and close step 12-speed XTR M9100 cassette 10T lowest sprocket realized by new Micro Spline freehub body construction The three largest sprockets are made from aluminum and the next five sprockets are made from titanium, to reduce weight to a minimum Beam Spider construction results in a lighter and stiffer cassette Hyperglide+: enhanced shifting speed and efficiency allows to pedal continuously while shifting up or down Better chain engagement and stronger retention for improved confidence over any terrain Weight: 367g (10-51T), 357g (10-45T)