The CeramicSpeed Oversized Pulley Wheel System is the secret to increasing the efficiency of your derailleur through friction reduction. This version is optimized for the Shimano Dura-Ace 9200 system. It is the standard version which does not feature coated bearings. Low-friction bearings help make your drivetrain more efficient than ever. A carbon cage keeps the weight low and the wheels protected while the included oil helps you maintain operation. The upper pulley has 13 teeth while the lower has 19. The CeramicSpeed Oversized Pulley Wheel System helps you get the most out of your high-end Dura-Ace groupset.