PRODUCT INFORMATION
These oversized pulleys fit the newest version of Dura-Ace R9200, Shimano's flagship 12-speed drivetrain. Plus, these are full ceramic meaning ceramic bearings AND races that give you the highest level of efficiency so you can go even faster with less energy. 

SEAL OPTIONS
Road Seals

By using the standard cage on your Shimano derailleur, you will feel the benefits of reduced articulation in the chain, while retaining accurate shifting; something that has been a negative side effect of other large pulley systems.