Stots Dovetail Template Master
You use this template master to make dovetail and box joint jig templates. You can use it to make templates of virtually any size. It runs about $50 plus another $30 for the router bits if you don't have them. One weird thing about this jig is that when you buy it you are actually agreeing that you will honor a three page license that states among other things that you will only use it in one sop, not loan it to others, etc. It's one of the oddest things I've ever seen, but seeing that the jigs purpose is basically to reproduce itself, I guess it makes sense. As a result of this license you almost never see this jig being sold on eBay. I suspect that Stots enforces their license and that eBay honors this.