This is a compact mount to accept a RPi4 in a case along with an external hdd and external powered USB hub.
There are two model variants, the additional (solar) version has an additional custout for a usb to 9 pin serial port (which was reuired for my solar monitoring solution (which this model was inspired by, as I needed 4 serial connections for monitoring the battery banks and 1 serial for monitoring the inverter, external hdd was used due to the continuous writes to the log files.
Works well printed at a 0.2 layer height.
The author marked this model as their own original creation.