When the time comes to replace your SRAM 11-speed X-Sync jockey wheels or you're looking to upgrade your non-XX1 derailleur to some ceramic bearing pulleys, pick up the X-Sync Ceramic Pulley Wheel Assembly Kit and get your drivetrain spinning smoothly again. The ceramic bearings help reduce friction for less wasted watts, increase stiffness that contributes to snappier shifting, drops some grams, and increases longevity. The tooth profile is similar to that of the 1x chainrings with tall square teeth edges that engage the chain and alternating sharp and narrow teeth to help manage chain retention. The bearings are packed with grease that is optimized for low friction and maximum protection and the kit comes with a syringe of 10ml extra grease for maintenance duties down the road.