NIUNIU Tennis material: high-quality rubber is used as a lining to ensure the elasticity, stability and durability of the ball. The outer layer is made of high-quality chemical fiber, which greatly improves the wear resistance of the ball surface.AICHUANG Easy to use: Use rubber bands to tie the ball to the base, hit the tennis racket or hand racket to the wall or throw it into the distance, use the perfect resilience of the rubber and the pulling force of the rope to put the tennis back into your hand,Without having to pick up the ball often Application: For beginners and intermediate tennis players, the coach is a good teaching tool. This is a safe tennis game, ideal for indoor and outdoor sports. Purpose: Line tennis is a tennis training accessory, which can help you better individual training tennis skills. At the same time, you can throw one of them to your pet so that the pet can happily train with you. Of course, when your training is over,you can also use tennis to perform comfortable foot and waist massage to relieve your fatigue Delivery Quantity: 3pcs, Size: diameter: 6.3CM; elastic force: 1.25-1.35M; rope length: about 3.8-4M Kind tips 1. Package content: only the above package content, excluding other products. 2. The size is measured manually, please allow 1-2 cm measurement error. 3. Due to different monitors and lighting effects, the actual color of the item may be slightly different from the color shown on the picture.