Shimano XTR M9100 cassette features better chain retention and ground clearance. This cassette is built with a strategic application of aluminum, titanium, and steel materials for an optimal blend of weight savings, rigidity, and durability. Compatible with Shimano Hyperglide+ chains Hyperglide+ technology offers better chain engagement, stronger retention, and smoother pedaling for greater power and confidence over rapidly changing terrain Micro Spline technology delivers lightweight aluminum freehub body to reduce weight and utilize a 10 tooth top gear