I'm not talking about police cuffs, but the type sold at Party City and other stores. This type has a "Stop" switch (like the double-lock) and a working pivot connecting the chain to the cuff. When an old one failed I took it apart and took a few pictures. I always break off the safety release and grind it down even further. This cuff has slots in the jaw and only a starwheel comes in contact with it. The way the pawl plate/lever works, the starwheel works as the ratchet.