Printing Settings
Height: .1 mm (I used a .2mm first layer height)
Walls: 4 or more
Top/Bottom/infill: all layers should be solid layers
Support: on
Material: Glow in the dark ABS shown in pictures, but anything will do so long as it meets your needs.
Make sure you mirror one side of the wallet or the other
The author remixed this model.
Added provisions to allow the elastic strap to not be a loop, as well as hold a Yubikey 5C on the opposing side. Both sides have been thickened by ~1.2mm to support the added features.