The SunRace MZ 12-Speed Cassette offers a wide ratio design. - Compatible with SRAM 12-speed rear derailleurs (Shimano rear derailleurs are not compatible) - Designed for use with HG freehub bodies, but not compatible with XD or Microspline freehub bodies - Spider, lockring, and spacer constructed from alloy - 7 Sprockets mounted on 2 spider carriers - Black chrome finish