This is a simple base to mount your Adafruit Perma-Proto ½ - sized board. To mount the board you will need the following:
The brass heatset inserts are the same type as used on Voron 3D printers. Link to the correct inserts from the official Voron BOM Sourcing Guide: https://www.aliexpress.com/item/4000232858343.html
If you haven't used heatset inserts before, they're incredibly handy. Once you start using them you'll wonder why you never used them earlier. They also come in smaller sizes like M2 and M2.5 which is handy for mounting Raspberry Pis and attached IO boards.
The author marked this model as their own original creation.