9 interlocked portions of spheres.
Thickness of the layers is 1mm, clearance is 0.5mm. Suitable for Strong and Flexible and Frosted Detail.
It would be also interesting to know if with the new Squishy material the layers could be disassembled and reassembled so that different colrs could be mixed. The thickness is only 1mm though, and 1.5 is recommended.
Be careful: the model arrived stuck: I had to use a lot of efforts to separate the layers, so buy it at your own risks!
Have a look at its ancestor: the Ring'n'Roll.
Breaking news: I find a mass-produced fidget which has a very similar concept: check the GyRing (not related to me nor to my shop).