Take charge of your strike today. Recommended for baseball and softball players of all skill levels aged 9 and up. Swingrails multi-patented design guides the players hands through the most important stage of swing and allows players to actually "feel" how to swing properly. A tear-off aid strap provides instant feedback and notifies the player when swing adjustments are required. Increases bat speed, power and swing plane, learn to stay in the ball and eliminate a long throwing swing, corrects dropping of hands and bat braking, prevents opening the front shoulder and promotes proper extension of arms, swinging short and long through the ball, trains hands to stay connected. For lower body. Corrects and prevents the arm from swinging includes 15 online instruction videos