Double case to fit 2 Raspberry Pi 3 - Model B+.
You need 12 (2,5 mm) "nut and bolt". Use 4 of them to mount the board to the base, and four more to mount the top to the base. Use the last four to attach the fan in the box.
I'm uploading 1 top with Domoticz and DeConz logo, and 1 top without logo.