Shimano CS-M7100 Cassette 12 Speed 10-45T BlackThe Shimano CS-M7100-12 Cassette. A twelve speed cassette that was made for smooth and easy shifting. Made with strong aluminum cogs as well as a steel inner piece for maximum durability and strength. Additionally, the CS-M7100 is sought after in the mountain biking and cross-country riding communities, because of the ease of shifting and the large array of gear possibilities. Available in 10-45T and 10-51T.192790444291