The SKLZ Bolt Balls were built for use with the SKLZ Lighting Bolt Pitching Machine. Ideal for soft toss, these lightweight foam practice balls allow for continual hitting practice. Ideal for players of all ages and skill levels, the small, 4” circumference size encourages players to focus more on the ball, which helps them remain focused throughout their training session. Soft practice balls can be used for safer practice or where less ball flight is necessary, such as at the park or in the backyard. Same practice value and no broken windows. Bolt Balls come in a pack of 12.