The SKLZ Quick Stick underload training bat develops hand-eye coordination by forcing batters to focus intently with the narrow-diameter barrel. With only 12 oz. of weight, batters can get in more swing and less fatigue. The lightweight design makes for fast rotation speed and hand speed training, or for pre-game warm-ups. The durable aluminum design is for use with practice balls only, not standard baseballs, so this package includes three practice balls so you can get started right away. Works well for baseball, slowpitch or fastpitch softball training.