I wouldn't be able to name it ...but it is a tool to separate the balancestaff from the "plate"...or some people use it also to separate the cannonpinion from its axle...!???
I really have no idea what it is for. I saw that in a magazine and thought it would be fun to solve. I went to a watch meet over the weekend and no one knew what it was used for. I guess we'll have to wait till the next issue comes out for them to give us the answer. I will let everyone know.