its 5 five part fully printable fidget toy.
I printed the top of the inner part with 100% infill.
This can be done in Cura by:
2. making it larger to increase the volume
3. in "per model settings" → “modify settings for overlaps” → "select setting" tick on infill density
4. set infill density to 99%
you can now check if it worked by going to the preview:
The author marked this model as their own original creation.