This small box allows you to load it with a D-sized ¼ TRS jack and attach it to the ProX case of the full sized Behringer Wing console. You can buy a pre-made cable/assembly or solder your own, and then connect it to the Headphone jack of the Behringer Wing. 
The factory headphone jack is typically hard to get to when the console is in a case, or in certain setups, so this puts a new connection in a more accessible area. 

I used V1 for mine because I hadn't decided on glue or possibly a magnet. Then settled on screws and drilled mine out. V2 simple has screw holes added to the build.
There is a backing plate in the design that is intended to be glued on, but I ended up not using it. It's optional. It serves no real purpose but aesthetics.

It is a remix, but with quite a few changes.