The CeramicSpeed Oversized Pulley Wheel System provides optimization and increased efficiency of the rear derailleur through its extremely low-friction bearings and unique overall design.

• Features 13-tooth upper and 19-tooth lower, aluminum pulley wheels with Grade 3 Silicon Nitride balls
• Robust cage crafted from polyamide and carbon fiber for durability and light weight
• Hardened steel bearing races
• Only compatible with Dura Ace 9100/9150 and Ultegra 8000-SS/8050-SS
• Not compatible with Ultegra 8000-GS or 8050-GS (medium cage) nor with the clutch equipped Ultegra RD RX800/RX805