ball joint massager turning spheres 3 axis bearing

It is a massager.
It is a ball join.
It is a 3 axis bearing.
It is a part which it is made from turning spheres.
sphere_bearing1.2 is a ball joint and a 3 axis bearing.
sphere_bearing4.1 is a good massager.
When you roll shere_bearng4.1 on your back you feel good.