Improve the performance of your 11-speed Shimano rear derailleur with pulleys that reduce friction and increase bearing life. Ours are designed to work with less friction, adding to the power transmitted to the rear wheel. There are choices available to best meet your needs. Machined aluminum pulleys with our Standard Bearings, which consist of our stock CeramicSpeed Balls installed in our hardened-steel races is the first option. These test better than anything else on the market. Machined titanium pulleys with our Standard Bearings is the second. Machined titanium pulleys with our stock CeramicSpeed Balls installed in coated, hardened-steel races is the third option. These are compatible with all 11-speed Shimano derailleurs