Consisting of a flat headed solid rivet and a copper washer. The rivet is put through from one side of the pieces to be joined, and the washer then placed over it as it emerges through on the other. The washer is then set in place by pushing it down with a setting tool. Something with a hole long enough to accept the rivet stub. The stub of the rivet is then either formed into a nice dome with a rivet snap, or gently peened into a closing lump with a small hammer. This is very simple stuff, and any amateur leather worker should be able to do it.