The ALEX wrist trainer Power-Roller is a versatile training device that has been specially developed to specifically strengthen the muscles in the hands, wrists and forearms. The faster you spin the ball, the more intensively your muscles work, which makes the training particularly effective. In addition to strengthening the fingers, wrists, arms and shoulders, the power roller also promotes coordination and blood circulation. It is also used to prevent and treat tendonitis, arthritis and carpal tunnel syndrome. This training device is ideal for sports such as tennis, squash, badminton, gymnastics, climbing and mountain biking, as well as for physiotherapy.