What is this, an open boxcar for train traveling ants? It's actually a PCB-or-really-anything holder for all the makers and designers who use DIN railing in their builds.
It's pretty simple, so not much to say about it. You have a DIN railing, you want to attach something to it? Maybe it fits in a 50mm x 80mm rectangle? This will do the job. Its easy to assemble in a minute or less. To install onto a DIN rail, attach the yellow plastic lock to the bottom of the holder and snap in once you have it positioned how you like. The plastic casing is easy to machine, drill or cut.
Note: DIN Rail is not included.