The Total Control BASEBALL Batting Ball helps baseball hitters develop strength and extension through the hitting zone. These balls are slightly smaller than than the TCB ORIGINAL Weighted Balls that are popular for fastpitch softball. At 2.9 inches in diameter (exact baseball size) and a weight of 15 oz, the design gives optimum resistance to the muscles used when hitting.The TCB ball provides instant feedback to the hitter upon contact. Hit it square or on the center line of the ball, and the shape remains round. If hit off center, the ball changes to a donut shape - spinning up or down depending on location of the contact of the ball. These training balls are used primarily for front and side toss. Start out slowly with 3 to 6 solid hits and increase to a maximum of 18 to 24 in one hitting session.