I'm thinking it some sort of release hook. With something in the Jaws and pulled from either or both of the side loops, then when a rope or what ever pulls the back loop, it releases the Jaws. Why?? the only thing I can think of it a Guilder,,,,,,,,,,,,,,no, well maybe some farm operation like stacking hay, or Damn don't it make you mad when you can't remember what you want to say :o)