The Wilson Portable Ball Machine combines state of the art portability with the performance you expect from Wilson. The first measure of a portable machine is its actual portability. The Wilson Portable Ball Machine is lighter 38 lbs. and more compact 22L x 14W x 20H than any ball machine with similar features. Plus, it includes a built in handle and towing wheels to enhance portability. The Wilson Portable Ball Machine also features TRAJECTORY CONTROL Variable from groundstroke to lob so you can practice all the shots, including overheads. SPEED CONTROL Adjustable from 10 MPH to 70 MPH. The slowest speeds are useful for younger players. The highest speeds are equivalent to professional level passing shots. INTERVAL CONTROL Sets the time between ball throws from one ball every 1 12 seconds for rapid volleys, to one ball every ten seconds. SPIN CONTROL Adjustable for flat shots, or for varying degrees of topspin or backspin. BUILT IN OSCILLATOR Delivers balls either in one position, or randomly across the court so you can practice hitting on the run. BATTERY LIFE Three to four hours per charge. Enough for a serious workout. And if you do need more battery life there is an optional External Battery Pack see Optional Accessories. ALL IN ONE CONTROL PANEL All functions are controlled by a single electronic control panel. In addition to the control functions it includes a battery charge indicator, and an automatic time delay so you can walk to your playing position after start up. WARRANTY The Wilson Portable Ball Machine is backed by a one year warranty covering both parts and labor. Extended warranties are available. Warranties are issued by the manufacturerlicensee. SPECIFICATIONS Weight 38 pounds Dimensions 22L x 14W x 20H Trajectories Groundstroke to lob Ball ejection speed 10 to 70 MPH Intervals 1 12 to 10 seconds Spin Topspin and Backspin Ball capacity 110 balls Oscillator Random Playing time 3 to 4 hours