The dorsal ball is a practical tool for learning to swim. As the child progresses and gains confidence, the balloon can be deflated to decrease buoyancy. A plastic clip allows for easy adjustment. Features: -Secure clip for easy adjustment -Inflation needle included -For beginner Waist circumference with ball: Size adjusted to smallest 26" and largest 28" without stretch; Possibility of gaining an additional 3" (31" in total) once the elastic is at its maximum.