Looks like 2 balls welded together with a small valley where they meet. Provides all the fun and bounce of a ball with greater stability. Sit or straddle, lay on stomach or back- a very versatile piece of equipment. Less threatening for the young child or those who are posturally or gravitationally insecure. Safer for in home or independent use by a child. Weight tested to 600 lbs - durable PVC vinyl, latex free. 3 sizes. *Colors change - and picture is not accurate, best to order by size!