Description Bottom brackets occasionally require removal for service, replacement, or upgrading. The Park Tool BB 16-notch BBT-19.2 is compatible with some bottom brackets that feature a 16-notch tool fitting, including most Shimano models with outboard bearings. Constructed from high-precision hardened chromoly steel, and can be driven using a wrench, socket, or 3/8″ drive wrench. PARK TOOL BB 16-NOTCH BBT-19.2 FEATURES Fits 16-notch threaded bottom bracket tool fittings with a 44-45 mm major diameter (outside of notches) and 42.7 mm minor diameter (inside of notches), including: Shimano BB80, BB5700, XT BB70, BB51, and previous external bearing threaded cups Campagnolo SRAM/Truvativ GXP Chris King FSA MegaExo Hope Race Face X-type Surly Wheels Manufacturing Fulcrum Also fits 16-notch Bafang BBSH, BBS02 mid-drive e-bike motor lockrings. Features a 3/8″ drive fitting and 1″ wrench flats NOTE: due to the shallow engagement of their tool fittings, the BBT-19.2 is not recommended for 16-notch disc brake rotor lockrings. Instead use the Park Tool BBT-9 or BBT-69.4.