Sensorial perceptions are very important in the motorial coordination both of eye-foot movement as well as eye-hand movement, and furthermore, in stimulating equilibrium and the correct position of the body in the space-time dimension. The special form of the Original Pezzi® Half Ball ø cm. 14 permits a more stable fixing to the floor and with the variation of pressure of the instrument, one is able to easily and efficiently vary the level of difficulty in the exercise. The raised grooves of the surface permit an intensive proprioceptive and reflexogenic activity. The half-balls are ideal for pre-skiing gymnastics, in preparation for group sports, proprioceptive exercises and equilibrium in postural gymnastics as well as rehabilitation in physiotherapy treatment of ankle pathologies.