Sometimes you're not totally done with your project and ready for a real housing, but you're sort of done and want to do some testing, but not worry if you're boards are shorting to whatever they're sitting on. Enter, this tray thing. It's just sort of a raft to screw down a full-sized Arduino and a 1/4-size Adafruit Perma Proto board. The screw holes all line up. The thing prints with material at the holes to grip #4 self-tapping screws. There is no lid, or even provisions for one. There are, however, four extra through holes in the bottom, so you can screw this to a board or some other part of your project. This is I thing I needed today, maybe it can help you, too.Flat side down and go! Except for the row of holes that is covered, the design clearance under the proto board is 0.20", so there is plenty of room for solder work.