model: 12/12t SHIM 11 Road compatible: Shimano 11 spd, Campy 12 spd, Etap 11/12 spd seal: road color: black/blue A fresh look at pulley design maximizing pulley size and improving padaling performance for any derailleur Redesigned shape of the pulley teeth now give better chain retention and accurate shifts every time Updates to newest version include: Increased stiffness using A-Shaped pillars between the bearings and teeth, maximized tooth count for every derailleur helps deliver optimal drivetrain performance, and enhanced visual design achieves a more cohesive look across the different models Road seal version runs with uber-efficient minimal contact seals to achieve the lowest friction Cross seal versions are built for leaving the beaten path, offering the best durability, regardless of the weather conditions Sold as pair