Classified cassettes are machined from one-piece steel, with a high durability coating to reduce wear. They're extremely light and designed to fit the unique driver interface of the Powershift hub. - Machined from High-grade, one-piece chromoly-steel for increased durability and reduced weight - Ultimate Gear Coverage: 24 gears, small steps, up to 530% of gearing range - Designed specifically for the Powershift hub - Cassette lock ring included