It's a simple clip-together design that requires no tools or extra screws. Use it as is for a complete enclosure, or if you need to access the GPIO pins if your Pi has them, simply cut out the thin bit covering them with a knife. There's also a slot for the camera cable.
While it's probably a little bit too compact for day to day use, it's ideal for protecting the Pi from the perils of your desk while developing projects.
The author remixed this model.