Please have a look at THE FOLDOVER DEVICE here
http://www.profession...8/nov98/1198fys1.html
After having read paragraphs 1, 2 and 3* I felt I understood what they were saying. I thought the wire was a fixture. But then they go on to say that it can be opened when going over the finger and that's what I don't get - how can it be, considering the ends of the wire have been soldered together and considering the little support is not flexible i.e. cannot be pushed into the ring. What am I missing? English is not my native language so it's very likely that I *am* missing something:)
*The foldover device is dealt with twice on the same page. I am referring to the way they explain it the first time, but do keep scrolling downwards after having read that one, as there are larger illustrations at the bottom of the page.