Can this machine toss regulation baseball？ Yes, this machine can toss tennisball, baseball and dimpled training balls. How many batteries do I need to start the machine? 8 x D batteries. Can 698BH launch softballs? No. Why is the machine unstable when used？ Placing the ball during machine startup can potentially cause this problem. Therefore it is recommended to place the ball before the machine starts. Where can I buy extra ball stacker? Ball stacker availabe at our amazon brand store. Previous page Next page 1 Toss Range 2 Launch Time 3 Extendable Stacker 4 Power Supply Speed & Height Adjustment You can modify the launch height and distance by turning the red button on the machine. It's important to note that the machine is delivered with factory default settings, including the minimum serve's height and distance. Previous page Extendable Spiral Ball Tunnel Compatible with 680BH, 6802BH, 3809BH, 6801BH, 666BH, 698BH. Learn More 9-Inch Dimpled Training Baseballs One dozen dimpled training baseballs, compatible with 698BH/666BH/777BH baseball machines. Learn More Next page