This is a simple customizable box with rounded corners and a slide on lid. All parameters are customizable and described in the .scad file.
Use OpenSCAD to edit the model.

No Supports needed.
Print with any layer height you like and 100% Infill or set the amount of permitters to a higher value. 

If you use a 0.4mm nozzle use 0.8, 1.2, 1.6mm and so on as thickness this will result in 2, 3, 4 permitters. Make sure to select the right amount of perimeter in your slicer software.