A marble box that can hold up to 25 marbles from Gravitrax. The diameter of Gravitrax marbles is 12.6mm, while the diameter of the hole shown on the bottom part is 13mm (0.2mm wider on each side).

I also added a Fusion 360 file for you to use it as a base for your own creations.

Enjoy!

UPDATE 10/1/2025: The top part has fillets which results in a uneven look between the two parts. For those who already downloaded the old files, please delete them all (except the bottom part) and redownload the new files.

UPDATE 11/1/2025: Reuploaded the wrong file of the top part so I reuploaded it again. For those who already downloaded the old files, please delete the top part you have downloaded earlier and redownload the newest top part.

And LOL, making these updates makes me feel like deleting this Thing and re-uploading it as a new Thing, but I didn't, which is why it is in one of my collections called "Things I almost deleted".