E*Thirteen Helix Race 12-Speed CassetteThe E*Thirteen Helix Race 12-Speed Cassette is here to change the game. Featuring more gear range than any other cassette on the market today, the E*Thirteen Helix is a premium 12-speed cassette that has a huge, 556% gear range. This 9-50-tooth cassette is split into two separate clusters, with the last ten gears separate from the first two granny gears. This makes it easy to replace only the gears that are worn when the time comes. The 9-36t Race Cluster is made out of steel for durability, while the first two climbing gears are aluminum for maximum weight savings. The Helix 12-speed race cassette is designed to work perfectly with SRAM and Shimano 12-speed drivetrains and is super-lightweight, weighing in at just 345 gramsFeatures Works with SRAM and Shimano 12- speed drivetrains First two gears are aluminum lightweight Last ten gears are made out of steel for durabilityLightweight 345g for the complete cassetteSpecificationsCassette Body TypeShimano/SRAM 12-speedCassette Cogs9, 11, 13, 15, 17, 20, 23, 27, 31, 36, 42, 50Drivetrain Speeds12Cassette MaterialSteel/aluminumFreehubXD and XDR drivers onlyWeight345 grams | e. thirteen | Helix Race Cassette 12 Speed Nickel | Grey | 9-50T