Jack-It Trainer Swinging Weight - Youth For the young ball player just starting out or looking to improve their game, the Jack-It Youth Trainer Swinging Weight will boost your confidence, power, and strength. Great for tee work, soft toss, and live batting practice, the weight goes on your bat in the optimal position that allows you to maintain proper swing mechanics. Made by ball players for ball players, the youth trainer will provide immediate results, quickly building bat speed and power so your confidence soars out of the park. It forces your hands to work properly by creating a shorter compact swing, resulting in improved technique. 5 oz.