1. Tennis trainer, tennis set, including 2 elastic balls, 21*5 cm, blue [High quality]. The base of the tennis trainer is made of high - density materials, which is very sturdy and durable. The tennis balls are made of chemical fiber wool fabric, with high wear resistance and good elasticity. The attached rubber rope is thick enough and long - lasting. In short, this set of tennis equipment is of good quality and practical. 2. [Water inlet and outlet] The tennis training equipment adopts a water inlet and outlet design. Fill the trainer with water or sand, and then use a non - slip design at the bottom, which can improve the stability of the trainer's base. The spherical groove design fits perfectly with the attached tennis balls. 3. [Self - learning tennis training] The rebound tennis ball with a rope is very useful for single - person tennis training. It can improve your attention, exercise ability, and hand - eye coordination ability. It is simple and practical. Of course, it can also help you acquire tennis skills during the self - learning process. 4. [Portable set] The tennis training set is very portable. Before filling it with water and sand, the tennis base is light and easy to carry. You can easily take the tennis trainer outdoors to start a unique training session. In addition, the accessories of the tennis trainer are simple and convenient to store. Note: The data is measured manually, so an error of 1 - 59 cm is allowed. Due to differences in light and the screen, there may be some color differences. The specific product shall prevail in kind. Thank you for purchasing products from our high - quality store. Have a nice day!