Product Description: Air delivery system with no moving wheels. Power source is a durable shop vacuum-derived blower fitted to a tubular structure. Motor-driven hopper on top rotates to drop ball in clear tube every 8 seconds. Each pitch will hit the strike zone in varying location. Sliding air gate adjusts speed of pitch. Pitches over 90 mph at 16-20 feet. Hopper holds up to 100 golf-ball sized plastic balls. Adjustable height via a multi-position "elevator plate" on front leg. No operator required to feed balls. Wiffle balls with holes move more and solid balls shoot faster. Indoor/outdoor use. You can also use with Swift Stik Training Bat to practice hand-eye coordination. Four dozen golf ball size perforated Wiffle balls included.