Prime 9 Technology is a counter-intuitive philosophy based on the less is more theory - it embraces range without adding complexityAdding an extra tooth to each of the three highest gears provides increased durability and decreased wear for the heavier loads of E-Bike ridingCompatible with standard HG style freehub bodiesUltra-wide ratio with consistent progressionSteel Stamped cogs pinned to lightweight spidersE-Bike optimized 12 tooth cassette gearing12-50t9sp12-14-16-18-22-28-34-42-50BlackUPC/EAN/GTIN: 616043832845