* Designed for smooth and fast shifting* Gradual gear progression between cogs — at least five one-tooth jumps on 10-28T, 10-30T and 10-33T cassettes — while still offering a wider range* 10-tooth start helps provide a wider gearing range* Designed to work with an XDR driver body* One-piece machined steel X-DOME design for weight savings* SRAM Model ID: CS-XG-1290-E1