I made those pen cups / drawer organizers to organize my pens and other stationery products. The smallest one is 70mm x 70mm in size and the others come in multiples of that: 2x1, 2x2 and 3x1.
The wall thicknes is about 1.5mm so printed in 0.3mm layer height and 0.5mm line with you only need three solid lines for the walls.
They can be connected to each other with a little connector piece.
The author hasn't provided the model origin yet.