This is just a simple bracket to allow some simple tact switches to be used as shoulder buttons for a gameboy zero. The only requirement is that the tact switches have to be 6 mm by 6mm and at least 9 mm long (12 mm long is recommended). You will see multiple sets of files, The set with circles are intended to be drill guides. Print those out, place them in the back shell, find bits that are close enough, drill using the holes as guides, discard the circle brackets. The set with square holes are intended to be the final brackets. Use hot glue to attach them in, wire up the tact switches, and then use hot glue to hold them down. The blank pair is used in case you want to create something in that space and mount something in.