Park tool bottom bracket tool bbt59this is a precision cnc machined aluminium tool for the installation and removal of 16 notch external bearing bottom brackets with an outside diameter of 41mm it is anodised for easy identification and features a ratchettorque wrench compatible 38 drive features cnc machined aluminium 41mm od cup fits shimano bbr60 ultegra 11 speed 6800 series shimano mt 800buypark tool workshopfrom chain reaction cycles the worlds largest online bike store