The SMAI Slam Ball Monster Set lives up to its name the set has three slam balls each coming in at 60kg, 70kg or 80kg in weight. This set is made for those wanting to take the challenge to the next level into Strongman Atlas Stone style training drills. Slam Balls, also referred to as Dead Balls, are constructed of a heavy-duty and durable rubber outer shell filled to weight with sand. The surface of the ball is pliable and tacky, this ensures that the ball is easy to grasp when used in drills.