Double sided bottom bracket lockring hook spanner one side is a single hook the other is a hook spanner with 3 notches for better engagement in the lockrings the three hook end will fit 3 notch lockrings with a maximum outside diameter of 46mm and minor diameter in the notches of 40mm the park tool hcw 5 crank and bottom bracket wrench featuers double ended tools save space in the workshop features the proven y head design that puts metal where it is needed for strength