This is designed for a Raspberry Pi 4 with the new POE+ HAT installed. It stands on it's side so the heat can escape more easy. The Pi is locked in place by the Ethernet cable.
There is a B version of the design with screw holes on the exterior, those are made for M2, the inner screw holes are made for countersunk M3 screws.
And a C version for two screws at the end of the construction.
Print with supports, it needs it in two places.
I have used PLA but it is better to use a PET because with the POE+ HAT the Pi will be very hot and PLA becomes yoghurt quickly :)
The author hasn't provided the model origin yet.