Features. Use for both ergonomic sitting and core exercises, supports childrens lower back and improves posture, chair has 4 wheels all lockable. Easy assembly required. Includes chair base, burstresistant ball and one hand pump. Balls and bases are made with PVC, free of phthalates, heavy metals and latexSpecifications. Ball Color Green. Origin Taiwan. Material PVC. Latex No. Phthalates No. Weight 1.5 lbs