I don't see how you could wrench anything with it. It looks more like a feeler gauge with three diameters.
It has a military application as well as commercial purposes. In theory, it could have an arming use in the right situation. A hint will be aviation. For those that want to "Google Cheat" a hint that will get you a result is it's nickname. Be visual on that one.
Well if it is a wrench, then those three half hemispheres fit into a slot and are twisted. It's a tool for some sort of screw fastener that doesn't require much leverage.
It's it..... What is it... Remember that Faith No More song Epic? I think of that song everytime i see this thread.
Ok, the first that wants to use the internet and post the next pic can use this hint: One of its nicknames is "Snoopy"
