Single Trainer：This is a great one-person tennis trainer with 3 tennis balls with rope. Tips: Tennis balls are consumables. It is recommended to replace them with new ones after a period of us High Quality and Durable：Tennis trainer is made of high-quality PE material, the tennis ball is made of thickened rubber inner liner and elastic nylon rope, which can achieve effective rebound and durable Clever Design：The top is a semi-circular groove design, tennis balls can be placed when not in use. The middle part is designed as an annular groove, which can place the elastic thread, thereby avoiding the trouble of entanglement and knotting, and is more conducive to storage Designed for Single Training：The tennis self trainer is equipped with high-quality elastic ball with 13 ft elastic string. When you hit the ball, the tennis ball will rebound again by the traction line to achieve the effect of repeated strikes.Do not hit the ball again before it bounces back to the ground Easy to Carry：The tennis training device is designed as a hollow structure kettle. After training, you can open the mouth of the bottle and pour out the water or sand inside. At the same time, a handle is added to the side to make carrying more convenient and comfortable