SKLZ Throw Trainer Ball - Teaching Tool for Proper Throwing Motion Raised seams for proper finger placement Rotation guide provides instant feedback Regulation size and weight baseball One ball for use by right handed or left handed players Increase muscle memory and accuracy Reduces the risk of throwing arm injuries while improving performance Utilizes scientifically designed and located raised seams to stimulate the mind-muscle link Raised seams improves finger, hand, and wrist positioning throughout the throwing motion Solid black strip down the middle of the ball give players instant feedback on arm angle and release Raised seams enhance release awareness and muscle memory