Sun Race CSMX80 11sp. Cassette 11-50TLightweight wide range mountain cassette compatible with HG 8 11sp freehub bodies 7075 aluminum 42t and 50t cogs, all other cogs are steel 7 cogs on 2 aluminum spiders, plus aluminum lockring and spacers SRAM derailleurs are generally compatible, Shimano derailleurs require a longer B tension screw (use WQ2299) TECH SPECS model CSMX80 freehub type HG speed 11 range 11 50 cogs 11,13,15,18,21,24,28,32,36,42,50 color black weight 519g