The CHAMPRO Weighted Baseball Training Set provides a way for players to improve their in-game performance. Many players agree that weight variation training can increase their velocity when playing with a regulation game ball. Train with the progressively heavier balls in this set to work on building arm strength and throwing velocity. CHAMPRO's weighted training baseballs have stripe patterns that allow pitchers to monitor the pitch rotation, helping them develop their skill set. These balls have raised seams and leather covers that are made to last. The set comes with 6 progressively heavier balls--one 7, 8, 9, 10, 11, and 12 oz ball.