Customize in Prusa Slicer with a name, logo, etc.
Lanyard
A lanyard can be attached at the two slots on each side. Guide the lanyard through both and secure it with a knot. This way the lanyerds pull the box closed when worn arround the neck.
Hinge
I originally went with the ball-and-dent hinge design, as this would make the box print in place. After the first proto it was clear that it would need quite some iterations and I figured the box needs something more reliable. The filament hinge brings some extra work after printing, but it's very easy to implement and highly reliable.
Cut some filament, about 5 mm longer than the hinge, insert and form both ends to a blob with a soldering iron or lighter. I some PETG for its ductility.
The author marked this model as their own original creation.