Detailed Product Description SS-K2-8 Flagship SeriesInnovation Human-oriented Idea.Micro-computer smart tennis ball machineThere are 32 kinds of program in the state of random mode(different conbinations of ball speed,fixed point,flat stroke, horizontal, vertical, lob, top spin, back spin, Wide- line, middle- line, narrow- line).Every program can be changed automatically (30 seconds/program).The ...