Rollerball (Spaceball, Gyrotwister, Gyroball) - hand and arm booster

It was developed in space navigation, against muscle atrophy in the state of weightlessness, and has now been transferred to everyday life.
The inner ring rotates at high speed (up to 10,000/min).
By continuously moving the wrist in a circular motion, the speed must be maintained, thus requiring an effort.
Using different movements (always starting from the wrist), you always move a different muscle group.

The Rollerball is a very useful structure that works on the principle of the gyroscope effect, and when it reaches 10,000 revolutions, it corresponds to a weight of 15 kg. Strengthens forearm and arm muscles while having fun. Especially recommended for climbers, tennis players, squash players, cyclists, but also perfect for rehabilitation and therapy purposes.