I have made small boxes to carry various delicate items in my backpack. This box protects them well when carrying, and I'm sure it can be used for many other purposes. The box is easy to customize directly on the original F360.
F360 source allows you to define the width, length, height, radius of corner rounding, and thickness of the bottom.
If you slice this with a Prusa slicer, you can use 0.3 layer height on most of the box and recommend 0.15 layers for the lid area of the box and the lid. Easy to print and no supports needed. I have been using 0.1 mm tolerances, and it is an excellent and tight fit when printing with PLA.
Model needs still some tweaking for PETG as current wall thickness does not play well this material!
Customize this to your will.
Edit:
fixed some model issues when changing parameters. V5 works better.
The author hasn't provided the model origin yet.