Yes4All Dynamic Slam Ball is specially designed to be thrown thousands of times without it breaking or being deformed. Engineered for intensive repetitive exercises, the slam ball is sand filled with PVC shell, which allow the ball to absorb the energy of a slam instead of bouncing or rolling away. The uniquely textured shell provides a non-slip grip for you to catch the ball easier. Yes4All Slam Ball features the seamless construction to prevent it from splitting over time of use. This is a suitable ball for exercises like wall slams, overhead throw, Russian twists & squats. Suitable tool for personal trainers, sport training like boxing, wrestling, & more.