The POWER-FLEXOR ® is a simple accessory, complete, evolutionary and silent, which engages jointly all the muscles and ligaments, hands on shoulders. Its regular use promotes the development of the force and power of the upper body, which today represents an essential element of efficiency and performance in many sports. The unique rotary action of the Power-Flexor develops specific muscles which affect the flexibility, not usually achieved with conventional exercises. The exercises are based on physiological principles which increase the strength of the wrists, forearms and shoulders. The patented function of Power-Flexor, sets the appropriate voltage to fit your exercises. The Power-Flexor is a simple accessory, complete, evolutionary and silent, which engages all the muscles and ligaments of the hands to the shoulders. Regular use promotes the development of the force and power of the upper body. Opinion of Dragon Bleu: The Power Flexor is nothing extraordinary to look, but it really works! It improves rapidly your grip and muscle resistance on wrist and forearm. A great found!