High QualityThe base of the tennis coach is made of high-density material, which is very strong and durable. The tennis rebound ball is made of chemical fiber wool fabric, which has strong wear resistance and good elasticity. The attached rubber rope is thick enough and durable. In short, the tennis set is of good quality and practical. Water Inlet and Outlet The tennis training equipment has a water inlet and outlet design. By filling the training tool with water or sand and then giving it a non-slip design at the bottom, the stability of the trainer base is improved. The spherical groove design fits perfectly on the tethered tennis ball. Self-Taught Tennis Training Rebound tennis with a rope is very useful for solo tennis practice, it can improve your concentration, exercise ability, and hand-eye coordination. Simple and easy to use.