Compatible with Shimano® Hollowtech II™ or other 16-notch ∅44mm external bearing bottom bracket cups and 16 notch rotor disc lockrings (incl. E-Thru axle hubs).Fits Shimano® BB Tool Adaptors TL-FC24 and TL-FC25.Specification:Functions: 1/2" Dr.Material: CNC machined hardened steel.Size: ∅55 x 45 mm