Check the listing for details. Outdoor Tennis Trainer Practice Rebound Ball Home Training Ball with String. Condition: New. Listed at 7.79 USD. Product weight: 60+10g Product size: Ball diameter approx. 6.3cm Elasticity approx. 1.4m Cord length 4m Product colour: yellow + black Product material:Felt shell + high elasticity rubber liner Description. 1. super elasticity, not constrained, 2.5m free fall elasticity 1.4 above fast rebound, no ball pick up trouble 2. Use anywhere with a tennis ball, suitable for beginners to learn the important moves of the racket 3. White wool, loose and strong wool, thin and even fibres without showing the bottom, no insects on the surface, firm glue seams without cracking 4. Hard rubber, newly upgraded with better elasticity and felt material, strong and durable, not easy to burst and more resistant to play. 5. Simple operation, easy to use, directly tie the rope knot can be used, strong and not easy to fall off the party alignment, the rope knot does not affect the hitting experience Package: 1* tennis ball