This is a case designed for the UK1541, which is an 1541 "replacement" device that allows you to mount D64 images and access them through your Commodore 64 as though it was connected to a real Commodore 1541 disk drive.
This design offers easy access to the SD card, top buttons, IEC port, and joystick port plug. It doesn't block any of the screen area, provides full visual access to the numerous LEDs, and keeps the IR receiver open. It is furthermore as compact a design as possible (only about 7mm wider than the board itself.
The side walls are 3mm thick, all corners are filleted for strength. The lid is thick for rigidity, but still allows for the surface mounted parts on the face of the board to not be impacted. Only four #4 screws are needed and can be removed to allow access to the back of the board should you need to replace the button battery.