拋球鎖腕器是網球最重要的技術．錯誤使用手腕很容易破壞穩定性和控制力、極易牌網球鎖腕器原理是通過固定手腕正確姿勢和快速形成肌肉的記憶、逹到最隹效果的輔肋工具。
 
        For-hand and Back-hand is most import in tennis .when will you make mistake on your wrist .the happenis unstable  and out of control. EEE-PLAY tennis wrist knottrainer.the principle is by fixing the wrist and product the muscle memory. to achieve the best effect of auxiliary tools.