KaRaDaStyle Plyo Ball Baseball Velocity Up Training Ball Pua Ball Sand Ball Eight Ball [Learn the Correct Throwing Motion with Plyo Training Balls] "I want to throw consistently fast pitches" and "I repeatedly hurt my shoulder and elbow." These are for those who fit these descriptions! This is a training ball that allows you to learn the correct throwing motion, making it less likely to get injured. 130g Set of 2 Some dirt and dust may be present. Will be packaged to prevent water damage and shipped.