Shimano HG50 7-Speed Cassettes.HG cassettes work with HG and IG90, 70, 51 and 31 chainsHG cassettes are not designed to work with IG30 and IG50 chainsItem SpecificationsColorBrownWeight301gIntended UseMountainCassette SpacingShimano/SRAM 7Cassette Body TypeShimano 7Cassette Cogs12,14,15,18,21,24,28Number of Speeds7Chain Compatibility3/32"Range12-28