how do I adjust a rest

I have just bought a spigarelli zero tolerance rest for a matrix. I was under the impression that the arm can be moved in or out; up or down. There are no instructions with it and, although it is obvious how to attach it to the bow, I cannot work out how to adjust it. Am I right in thinking these are adjustable? If so, how does one do it??! The other problem is that I prefer to use the plunger in the front hole, and the rest appears to only reach as far as the back one. Is this something I...

how do I adjust a rest