The enclosure is tall enough to allow for female connectors to be placed on the Pi's GPIO headers without bumping into the ceiling when mounted. There is a zip tie anchor feature to allow securing the power cable to the enclosure to provide strain relief. There are four spots for M2.5 heat set inserts for securing the Pi, and the ventilated section has spots for 2 M2.5 heat set inserts for mounting an Adafruit STEMMA QT sensor breakout board (or anything with similarly-spaced mounting holes).
The heat-set insert holes were designed for McMaster M2.5 x 0.45 mm Thread Size, 3.4 mm Installed Length inserts (part number 94180A321) and are not open, so do not use screws longer than 5mm.
The author hasn't provided the model origin yet.