Constructed from precisionmachined 4140 steel the BBT13512 is a heavy duty tool for the removal and installation of select bicycle components with an 12notch tool fitting \n Features an extra deep body to accommodate extra wide spindles and low profile walls at the point of engagement for recessed lockrings \n Fits 12notch 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 \n Three methods of tool engagement include a 3/8" drive fitting, a 1" hex fitting, and 36mm wrench flats