The Shimano Dura-Ace CS-9000 11 Speed Cassette is Shimano's top of the line cassette built for the top riders. To make sure that you get exactly what you're looking for from this cassette, Shimano has introduced “Rider-tuning” with the Dura-Ace CS-9000. The Dura-Ace CS-9000 is set on a carbon fiber mid spider carrier and all sprockets that are 16 teeth and larger are made of titanium to help shed weight without sacrificing performance. The sprocket sizes are 12-13-14-15-16-17-19-21-23-25-28. This cassette features a 12-28 ratio and includes a lockring and the technical manual.