A precision CNC-machined aluminum tool for the installation and removal of select threaded bottom brackets with 16-notch tool fittings, including Shimano Ultegra BBR60 and Deore XT MT-800 bottom bracketsThe BBT-59.3 features integrated threads for full compatibility with the Park Tool BBT-RS Bottom Bracket Tool Retaining System (sold separately)Fits 16-notch threaded bottom bracket tool fittings with a major diameter (outside of notches) of 4142 mm and a minor diameter (inside of notches) of 39 mmExternal BB SocketGrey16-Notch41-42mmBBT-59.33/8`UPC/EAN/GTIN: 763477001627