Specification: Type: Tennis Self-study Device Quantity: 1PC Material: Plastic+Rubber Color: As shown Elastic line length: 3.8~4 meters Base Size: 20*14*5.5cm/7.86*5.50*2.16inch Package include: 1*Tennis trainer 1. The base comes with the stopper that allows you to place the sand or water inside it to add the weight. 2. The small ring aside can help you tie the string, while the concave part can place the tennis ball. 3. This tennis trainer is lightweight, convenient, practical, easy to use, and can provide stable training support, contributing to single-player exercises. It can also improve your attention, athletic ability, and hand-eye coordination, and develop your interest in sports. 4. The elastic band can be tied on the heavy objects or directly tied on the triangular area of the racket. So you can use it to do the practice simply and conveniently. 5. A wonderful gift for your friends, family members, and kids who like playing tennis. And it can help you improve your steps, accurate control, and tennis skills in garden, park, and so on.