These Dura-Ace pulleys are stock OEM replacements for any RD-9000 rear derailleur, and as such will deliver original Shimano quality and performance. Get more life out of the rear derailleur and keep the drivetrain smooth and friction-free. Includes both pulley wheels for a complete rear derailleur overhaul. When it comes to servicing your Dura-Ace derailleur, accept no substitute and do not venture in the aftermarket. Success and perfection is guaranteed with these RD-9000 pulleys.