1/4" Cast Acrylic. Working beautifully to keep my latest electronics project in one piece. I burned one of the speaker holes with a bad path. But I figure this is just a prototype. Final version will probably have more mount points for additional hardware.
I am working on a speaker enclosure too. I going to put a pi zero running Volumio in it.
Got a few more tweaks on the design, but should be soon.
Very nice, I like to see the inside of things