Raspberry Pi table holder

I am building up a Pilab at the code club and makerspace that I am creating in my local community for kids. I wanted to be able to fasten the Pi's to the table, but I still wanted to be able to remove them from the bracket if I need to.

The Pi's are fastened with two M3 nuts and screws (10mm), and the holder itself is simply screwed onto the tables here.

This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/cAle2E1aJq3