The OSPW X System reduces friction by 35-40% compared to the standard pulley configuration. The lightweight, custom-printed carbon fiber cage ensures durability. This design allows for the use of the same chain length as the original pulleys. The profiles of the 14-tooth upper pulley and the 18-tooth lower pulley ensure stable chain retention without additional friction. The OSPW X System is developed, designed, and hand-built in Denmark - and tested and proven globally. Compatible only with specific derailleurs for 1X drivetrains. In the package: Complete OSPW X System for Shimano XT/XTR 1x12 CeramicSpeed UFO TECH Bearing Oil 15 ml dropper bottle for pulleys Decal