Kcs Yubikey cover

There are already some great designs for Yubikey cases/covers, e.g.
https://www.thingiverse.com/thing:532575
https://www.thingiverse.com/thing:2588513
https://www.thingiverse.com/thing:3760606
https://www.thingiverse.com/thing:2379775

However, I couldn't find what I was after, so I built my own.

My design goals were:
- no vitamins needed (screws, etc.): the Yubikey should snap in without any need for additional tools
- printable without support
- as compact as possible without sacrificing stability
- the Yubikey should be easily extractable, but not so easy that it would unintentionally fall out of the cover
- it should be attachable to a key chain

So this is what I came up with... have fun :)