Full X-SYNC for best-ever inboard and outboard shifting performance under load with optimized gear steps on low endUtilizes hardened tool steel machined X-Dome design for the cluster and stamped steel 38T and 44Tcogs are pinned to the lighter weight aluminum 12th gear55mm chainline compatibility for more moderate chain angle, longer wear and greater precisionUtilizes well accepted and broadly available XD driverbody10-52t12sp10,12,14,16,18,21,24,28,32,38,44,52Silver/Black341gXDUPC/EAN/GTIN: 710845891441