For a project that I'm currently working on, I'm going to be buying a ball head for a tripod. Its not going on a tripod, but more so on a suction cup (more on this later). Something like this is what I was going to get. It says on the page that the thread size is 3/8", which I've got no problem with. But my only question is whether this is a stud with the thread cut on the outside, or a hole with a thread cut on the inside. Its going to change the style of the mount that i'm making for the ball head. So if anyone knows which way round these things normally are, I'd be very very much appreciative.