Is Adjustable Locking Hub the only name for this kind of joint?

It has teeth like a Hirth Coupling but works kind of like a Bushed pin coupling. It has like 2 circles with teeth that have a hole in the middle. a bolt goes through the middle. Tighten the bolt to lock the two halves and loosen it to adjust them. Ive seen them used on things like wall speaker mounts and some adjustable arms for lamps and such.