Synopsis: 8-Notch Bottom Bracket/Lockring Tool Compatible with Shimano Octalink, ISIS Drive, Bosch Gen 3 and 4, Brose, etc. Bike Chainring Lockring Tool Compatible with: Shimano Octalink right side bottom bracket cups with external notches, ISIS Drive bottom bracket cups including Truvativ and Bontrager E-Bike Chainring Lockring Tool Compatible with: Front chainring lockring for Bosch Gen 3 and Gen 4 e-bike systems, Specialized Levo Brose e-bike systems and other lockring with 8 external notches With 8 notch, Each tooth is approximately 3.9mm wide and with notch spaced approximately 13.5 mm apart, Material: High Carbon Steel, Weight: 93g Maximum outside diameter is 43.5 mm. The width from inside to inside is approximately 38 mm.The hole in the center of the casting is 0.9 inches (22.5 mm) and will not fit on a 30 mm shaft. Bike 8 Notch Bottom Bracket Chainring Lockring Removal Tool