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. Can be deflated to 1in thickness (mushy) or inflated to 2in thickness (firm). Each disc has one nubby side for tactile feedback and stimulation and one flat side.
35 cm diameter (13.8 inch) disc.
*R,G,B,Y,BLK for red, green, blue yellow, black