The DynaFlex gives you the competitive edge no matter what instrument you play. This hand-held gyroscope builds and conditions hands, wrist and forearms, while also hand increasing speed and endurance. is like a personal musician gym in your hand. Simply start the rotation and then with a tilting motion, build the gyroscope Speed and Feel the Burn. Ideal for toning the muscles when away from your instrument or for pre-show warm-up. In conjunction with the Planet Waves vari-grip for the fingers, hands and arm workout.