CanDo Inflatable Vestibular Balance Disc, 13.8" diameter, Silver Inflatable disc mimics the movement and shape of an inflatable ball when used on any seat Relieves back pain, and improves posture when used while sitting Enhances your workout when used on the floor as a standing disc for balance training, and core strengthening exercises Great for children who have trouble sitting still, to increase attention and focus Features one flat side, and one nubby side for tactile feedback and stimulation