An extension or boom for camera work.
Ha ha, a friend bought one of these to attach his camera to varying surfaces. Of course now I have to come up with something and I keep complaining about being out of interesting subjects. sigh.Technically speaking this is a compact and handy mount for getting support from tubes, fences, tree branches, table edges, chairs etc but since the joint mechanism is the same I'll accept the answer because it's an extension nevertheless.
Apparently I can only come up with something that is identified either instantly or never so I'll leave the stage to you
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