Park Tool BBT-179 Steel Bottom Bracket Tool Description: The Park Tool BBT-179 Steel Bottom Bracket Tool is a rugged, shop-quality tool specifically designed for the installation and removal of select bottom brackets with 12-notch tool fittings. Precisely machined 4140 tool steel ensures long life, and a 3/8" ratchet, a 1" hex fitting, and 36mm wrench flats give plenty of options for applying the leverage needed to remove the most stubborn components. Note: This tool is not rated for use with impact tools/drivers. Features: Constructed from precision-machined 4140 steel the BBT-179 is a heavy-duty tool for the removal and installation of select bicycle components with a 12-notch tool fitting Features an extra deep body to accommodate extra wide spindles and low profile walls at the point of engagement for recessed lockrings Fits 12-notch threaded bottom bracket tool fittings with a major diameter (outside of notches) of 45-47mm and a minor diameter (inside of notches) of 44mm Three methods of tool engagement include a 3/8" drive fitting, a 1" hex fitting, and 36mm wrench flats Can be used to install/remove (among others): SRAM BSA DUB Bottom Brackets Race Face Cinch Bottom Bracket Rotor BSA30 Zipp Vuma Hawk Racing BB3086