This is a box designed for Volcano-type nozzles with embedded magnets. The magnets can be inserted mid-print or glued after it has finished. It also has a dedicated groove for small labels under each column.
It was created in FreeCAD and I tried my best to make it customizable only by editing the spreadsheet inside the file. You can modify number of columns and rows for nozzles and magnet height/diameter. Sometimes the model fails to recompute (probably because of the topological naming problem in FreeCAD) so it is not completely foolproof.
The STLs provided are for 2x2 nozzle grid and for specific magnets that I had lying aroud.