The second free shipping fee Re-bound Ball So-lo Tennis Trainer for Tennis Trainer Training Equipment for Self Practice Portable Tennis Training Tool Features: The tether cord is connected to a base that serves as an anchor, allowing the ball to Bounc -BACK for another volley! Made of materials, it has strong, durable, and designed to take powerful shots! Super-easy to use, simply FILLing the base with water to give it weight to counter the ball’s motion. The weight of FILLing water can Reaching 3 pounds, FILLing sand 5 pounds. Its lightweight construction, when empty, allows you to bring it with you anywhere you’d like to practice! Free yourself from the hassle of the need to go to the tennis court to practice your volley and hot. It’s a perfect training tool for both novice and professionals alike. The Tennis Trainer gives you the freedoms to practice anytime, anywhere, and all by yourself! Size: 22x5cm/8.7x2inch Package includes: A set of Tennis Trainer outdoor sports exercise bike exercise equipment