The Shimano XTR CS M9000 11 speed Cassette uses computer designed teeth and gates to ensure that your chain is able to smoothly shift across the entire range. The four carriers are carbon fiber and the range is from 11 40 teeth. To reduce weight, the 19,21,24,27,31, and 35t cogs are machined from titanium. This was done to decrease weight and increase durability. All of the cogs have also been drilled to further reduce weight. But don't worry, no strength was compromised in the machined designs. As far as usability, the M9000 fits on 8 , 9 , and 10 speed hubs in addition to 11 speed. It is designed to work with a standard dual chainring, but has been thoughtfully designed to accommodate a single one by configuration as well.