Morgan slam balls are designed for workouts that require a ball to be dropped, thrown, and/or slammed and are different from regular medicine balls. It is popular among fitness enthusiasts with over 10,000 Morgan slam balls sold per year. Our slam balls are constructed with an ultra-durable and heavy-duty rubber shell filled with fine sand for fluid movement. A rough (tyre tread) surface allows for a high-quality grip even when wet. Each Morgan slam ball comes with an sunken air valve to adjust air capacity and overall firmness. It also acts as a safety feature to soften the blow. Avoid using this item on direct concrete or any hard surface. When inflating the ball, ensure that the needle is lubricated with Vaseline for easy entry into the valve.