The CeramicSpeed Oversized Pulley Wheel System X is an excellent way to get the smoothest and most reliable performance out of your derailleur. This version includes coated bearings for the fastest and smoothest function possible with long lasting results. It reduces friction and optimizes the efficiency of your groupset. This version is made to accommodate your Shimano GRX 2x groupset. The OSPW X is designed specifically to thrive in off-road conditions. Gravel and cross riders have used this OSPW at the highest level, including races like Paris-Roubaix. It has a lightweight molded carbon fiber cage and customizable spring tension for a lightweight and customizable setup. The OSPW X runs over 40 percent smoother than a stock pulley. The CeramicSpeed OSPW X is a great way to enhance your gravel drivetrain.