Balance Disc - Massage SurfaceLong massage nodules on one side, with smaller nodules on the other side for a gentler massage The cushion can be used as a balance cushion to improve your sense of equilibrium, coordination, reaction and motor skills, it is also ideal for muscle exercise and toning. Can be inflated or deflated to change level of stability. You can adjust air by inflating and deflating the air through the valve inside. Used for lying, kneeling, sitting, standing and