Crafted of lightweight plastic, the Franklin Major League Baseball Aero-Strike Baseballs are perfect for batting practice or hitting drills. The Aero-Strike Baseballs (comes in a pack of 6) are 9” and are great for use with wooden bats, aluminum bats, plastic bats or foam bats. Franklin Sports Aero-Strike Training Balls are fully battable and are safe to use while young children and beginners are learning the game.