SHIMANO SM-RTAD05 6-Bolt to Centerlock Disc Brake Rotor Adapter Adapts standard 6-bolt rotors to Center-Lock hubs Does not fit 2-piece rotors with aluminum spiders like Shimano RT86 or RT76 6-bolt rotors Lockring uses Shimano Hollowtech II standard cup installation tool ***Cannot be used with the 6-bolt disc brake rotor that is installed with an aluminum adapter (SM-RT86/RT76)*** Original Shimano parts guarantee that all components work perfectly for optimum performance and maximum safety and longevity.