Hamburg 8 Handcuffs
This is an escape cuff from yesteryear. When folded (only in one direction) the cuff mechanism allows the cuffs to be opened. When fully extended, the bows, when pressed down, will lock. To unlock the cuff a key needs to be inserted into the lock case. The key pushes the bolt out of the way and allows the cuffs to open. The cuffs come with one of two keyhole shapes:
1. Fluted Key - a key that is so formed as to prevent casual picking of the mechanism.
2. Flat Key - a key that is just a flat piece of steel. MUCH easier to pick.