By limiting the angle of the elbow, you can learn more efficiently; 3 color variations; Securing the arm in half 90 degrees back and forth, and shaking the arm with the image of pendulum movement around the shoulder, helping to create smooth and rhythmic arm swings and pelvic twists. ■ When pulling the arm backward, the point is that the shoulder blades can be moved. ■ Suitable Height: 57.1 - 72.8 inches (145 - 185 cm) Expected Effectiveness ● By combining the arm into a triangle of around 90 degrees, it helps to prevent arm swirling. The rubber contraction allows the arms to be cut forward quickly and easily. Main training examples: Arm swings in stands, walking trolling (70% to 90% runs), assistance in jumping and triple jumps.