This is a 0.5U (1 screw height) Raspberry Pi Zero W tray. This remix of the original cuts off a good chunk of it, adds mounting holes for a Raspberry Pi Zero and a pocket for ventilation.

The screws needed to mount the Raspberry Pi Zero W are M2.5, the length is up to you, I'd recommend at least a 4mm length. There is no port access modeled, it's just meant to be a blank plate and have the ports accessible on the inside of the MicroLab.