Exercises your whole body, especially the shoulders, back, hips and arms. Helps keep your muscles loosened-up, good for improving co-ordination.
English translation soon!
Either: Hold the round hand grip on the rotating disc with one hand. Turn the disc one way and then change direction. Repeat using the other hand.
Or: hold one hand grip on the rotating disc with each hand. Turn the disc in one direction. Continue holding on to the hand grips and follow the movement around by turning on the spot.