The case comes in 9 layers of laser cut Acrylic plate, stacked and screwed together with M3 bolt and nut. You just need to remove the Acrylic plates, insert the Raspberry Pi 3A+ onto base layer and stack the rest of Acrylic accordingly, then screw it back again :) Don't forget to peel off the protection sheet on every acrylic plate. The USB port (only 1), HDMI, USB microB, Audio/Video jack, microSD card slot, etc are nicely fit and accesible too.
The top layer comes with holes for cooling fan (included), yet that is optional.
Get the case here: https://www.cytron.io/p-acrylic-case-...
Raspberry Pi 3A+: https://www.cytron.io/p-raspberry-pi-...