Shimano Ultegra Rear Freehub

Shimano's Ultegra Rear Freehub is the durable, lightweight heart of a race-ready rear wheel. Super-polished ball races house ultra-smooth bearings to minimize rolling resistance and the hub's oversize aluminum shell boosts wheel stiffness and responsiveness. Plus, Shimano's labyrinth seals shut out dust, dirt and water for phenomenal durability. And, you get Shimano's superb quick-release skewer, too.