The GX Eagle Transmission (T-Type) Cassette is a key reason why Eagle Transmission offers the best-ever inboard and outboard shifting performance under load. Thanks to its full X-SYNC design, the harder you pedal, the better it shifts.* Designed for a 55mm chainline * Optimized 520% range with larger 38 and 44-teeth cogs prior to the 52-tooth cog* Clearly marked Setup Cog for simple and foolproof installation* Pindome design for gears 1-8 and a single piece mini-cluster for gears 9-12.* SRAM Model ID: CS-XS-1275-A1