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 drag, adding to the power transmitted to the rear wheel. - Uses low-drag, long-life Standard Bearing with hardened-steel races and our super-round CeramicSpeed balls. - A set consists of differing upper and lower pulleys: they are marked as such and have directional arrows etched on them so you know exactly how to install them. - These pulleys are compatible with all Shimano 11-speed rear derailleurs except XT or XTR. - The kits come with CeramicSpeed oil in a 15ml dropper bottle. The bearings come pre-oiled. In the box: - 2 x 11-tooth pulley wheels - 4 x spacers - CeramicSpeed Bearing Oil in 15 ml dropper bottle - Sticker sheet