You're a ball player whose confidence should soar out of the park. You'll quickly develop confidence, bat speed, and power with the easy to use Jack-It Fast Pitch Hitting Jack-It System. Made by ball players for ball players, it's the only variable weighted hitting system on the market today. This patented live batting practice mechanism helps promote proper swing mechanics, and keeps you from casting. It strengthens your hands and forearms, while also forcing your hands to work properly by creating a shorter compact swing. Includes 5, 9, and 12 ounce weight options.