Park Tool BBT-135-12 Steel Bottom Bracket Tool (Black) (12-Notch) Description: The Park Tool BBT-135-12 Steel Bottom Bracket Tool is a precision-machined steel tool for the installation and removal of select bottom brackets with 12-notch tool fittings, including Praxis Works M30. Engraved for easy identification and featuring a ratchet/torque wrench-compatible 3/8" drive. Features: Constructed from precision-machined 4140 steel Extra deep body accommodates extra wide spindles and low profile walls at the point of engagement for recessed lockrings Compatible with Park Tool BBT-RS Bottom Bracket Tool Retainer Fits 12-notch threaded bottom bracket tool fittings with a major diameter (outside of notches) of 48-50mm and a minor diameter (inside of notches) of 46.3mm Three methods of tool engagement: 3/8" drive fitting, a 1" hex fitting, or 36mm wrench flats Specifications: Material: Steel Color: Black