SRAM XG1297 10-52 12s XD BLACK EAGLE T-TYPEFull X SYNC for best ever inboard and outboard shifting performance under load with optimized gear steps on low end Utilizes hardened tool steel machined X Dome design for the cluster and stamped steel 38T and 44Tcogs are pinned to the lighter weight aluminum 12th gear 55mm chainline compatibility for more moderate chain angle, longer wear and greater precision Utilizes well accepted and broadly available XD driverbody