PowerStretch inflatable Balance Stability Disc mimics both the movement and shape of the inflatable cushion when used on any seat. It acts as a dynamic cushion to activate major muscle groups. Use it on the floor as a standing disc for balance training, proprioception and strengthening of the lower extremities. Each disc has one nubby side for tactile feedback and stimulation and one flat side. The product is bundled with inflator and a measuring tape.