The tennis trainer is lightweight convenient practical easy to use and and can provide stable training support contributing to single-player exercise. It can also improve your attention athletic ability and hand-eye coordination and develop your interest in sports feature: The base is made of high-quality plastic to feature sturdy and durable factor while the rubber rope comes with high elasticity and durability. The bases comes with the stopper that allows you to place the sand or water inside it to add the weight the small ring aside can help you tie the string while the concave part can place the tennis ball.