This is a holder for watercolors, designed to be inserted into a tin (I fastened it with a magnet) to allow easy exchange of empty pots.
I have included the original FreeCAD file as well as four pre-exported STL models.
The FreeCAD file is parametric, so you should be able to change the dimensions of the base sketch and it should automatically derive everything else for you.
The author marked this model as their own original creation.