Park Tool HCW-5 Lockring Spanner.
Hakenschlüssel / Konterringschlüssel
Hergestellt aus Werkzeugstahl, lasergeschnitten
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