Park tool bb lock ring hook spanner hcw5double 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 note the hcw 5 is designed for bottom bracket lockrings for fixed gear lockring use the hcw 17 buy park tool bb tools from chain reaction cycles the worlds largest