The PowerNet Weighted Training Balls are designed to help hitters drive the barrel through the ball following through completely. The smaller ball forces the hitter's eyes to focus better which results in a more efficient path. Instantly know square hits versus mis-hits. As the hitter gets stronger and their swing begins to easily accelerate through one weight, they can move up to the next weight class. Also great for warm-up tosses before throwing a real baseball or softball. Read more.