https://www.bike-components.de/en/KCNC/Jockey-Wheels-System-with-Ceramic-Bearings-p54215/
Sale Special: KCNC Jockey Wheels: High-quality derailleur pulleys with ceramic bearings for Shimano Dura Ace and Ultegra. Smooth running, CNC-machined, 14/16...
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