SHIMANO Dura-Ace RT-CL900 Center Lock Disc Brake Rotor
Quieter than ever, but with superb, consistent braking performance on any long, steep descents thanks to excellent heat dissipation
The new arm shape is more robust, leading to quieter operation
Heat dissipation paint boosts performance
External lockrings are mostly needed on 15mm axle bikes
Internal lockrings are for 12mm thru axles.