The amazing Activity Sound Ball is just perfect for group activities. With the transparent clear casing you can see the balls inside swirling around the Activity Sound Ball creating a super element of fun and listen out as the bells chime away. The Activity Sound Ball is also great for floor time and therapy games. The bouncing of the Activity Sound Ball promotes visual tracking. Their sounds enhance auditory discrimination. Because sounds change with the motion of the ball, the Activity Sound Ball encourages experimentation. Measuring a fantastic 55cm in diameter and built and designed from the highest quality synthetic resin materials.