These headphone stands are made from the upcycled internals of old pressure gauges. The bourdon tube is acting as a spring now, instead of as a pressure vessel. When the headphones are loaded onto the curved tube their weight causes the tube to compress, this turns the pointer and therefore gives a reading. The scale has been re-calibrated to tell others in the room whether the headphone user is available for conversation or not.
The bourdon tube assembly is mounted in a piece of solid yew, so it is the Yew Tube.
A very limited edition of 6 in total.