SPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallSPEEDO Exercise BallInflatable exercise ball.Maximizes stretching and increases flexability.Improves ballance and coordination.Color is determined by size; Blue = 25", Purple = 30", Yellow = 35" This exercises ball is a great tool for advanced balance, and muscular strength, especially for the abdominal.You may also use it to improve posture and use it as your office chair.Add a Having a Ball Workout Video/DVD032 for maximum results.