This is quite a unique adapter, allowing devices attached to the end of a straight stand to be angled. Some might think that using a boom stand renders this redundant but this remains useful for things like adjusting the angle of a stereo bar - a boom arm joint may not be able to hold a loaded stereo bar reliably. I also find this useful for angling a handheld recorder on the end of a short boom pole or selfie stick (with 1/4" fitment adapter).
To fix the orientation of whatever is screwed into the end of the adapter, you have to use the two thumb wheels. This works, but is slightly awkward and I wish there was a better solution.
It is mostly well-made and high quality, most of it is metal. I encountered a problem when the button in the hinge screw popped out - extra caution is probably advised when push-turning the adjustment lever. Thomann were extremely helpful in dealing with this.