The rollers are a comparable size to my stamp cubes (4×4×4 cm). There are 6 rollers with the following themes and have a stamp o each end:
You can use them to stamp and print into modeling clay or kinetic sand. The rollers develop fine motor skills, vocabulary (create stories), and imagination.
It works when printed with PLA or PETG, else I didn't try.
The author marked this model as their own original creation.