Promotes good posture during long periods of sitting at home, school or in the office. Sitting on the ball requires use of the trunk and abdominal muscles. Can be used for stretching and exercise. Its five stabilizers keep the SitSolution from rolling away. This is particularly helpful in gyms, fitness and rehab centers. SitSolution is the well-behaved ball that stays where you put it! Of special interest is the Maxafe™ line of products, made with a patented Flexton Silpower™ material, to aid in slow deflation in case of ball puncture. Sold individually in polybag.