3 years & up. Non-roll away weighted ball offers a flexible chair for increased focus and improved performance. Reduces fidgeting and increases concentration with an original weighting feature that prevents the ball from rolling, keeping it in place when not in use. Builds core strength and a healthy posture, and keeps the mind engaged as the constant ball movements increase blood flow to the brain. Anti-burst, slip-resistant high-quality material. Safety tested and latex free. Includes pump, 2 stoppers, measuring tape and a stopper remover. Size: 55cm diameter – for children and adults between 5′ and 5’6″ tall.