... 3)one year replacement. 4)Internal shooting system SS-K1-5 Elegant SeriesHigh Quality Pretty EleganceMicro-computer smart tennis ball machinel ... frequency ,work/pause, fixed point/flat stroke, horizontal/vertical, lob,random, top spin, back spin, forehand and backhand middle-line.l ... 4.Double power, AC110V-240V, DC12V available.l 5.Ball speed : 30-150 km/hr (remote control speed adjustment ...