Shimano CenterLock Rotor Adapter SM-RTAD05. This adapter is for converting your standard 6-bolt hole disc hub to accommodate a center lock disc rotor. It uses the proven Centre-Lock lockring fixing system for quick and easy installation. Easily and neatly adapts your 6-bolt rotors to fit on to Centre-Lock hubs. The lockring uses the Shimano Hollowtech II standard cup installation tool. For use with rotors of up to 203mm. Weight: 54 grams. Note: Does not fit 2-piece rotors with aluminum spiders like Shimano RT86 or RT76 6-bolt rotors.