AppleRound Jr. Inflatable Seat Cushion with Pump, 31cm/12in Diameter, Sensory Wiggle Seat for Kids 12in/31cm in diameter for kids, small round dimples on one side for active sitting and even surface on the reverse side for increased comfort. Suitable for children to use in kindergartens and elementary schools. Recommended for ages 3 to 13. One free hand pump included for easy adjustment of cushion firmness to desired level. Good for active sitting, helps promote better posture, improve balance & coordination. Used as a wiggle seat to provide sensory input, it can effectively help kids stay focus. How to adjust air pressure: Remove the inserted white plug (air stopper) from the seat edge first, insert the tip of the pump into the mouth to inflate, then replace the plug back quickly when seat reaches desired firmness level. Durable & Safe: Lab tested, contains no US banned phthalates and heavy metal elements. Conforms to the safety requirements of EU EN71, US CPSIA & ASTM F963. Safe to use. Seller Warranty: Should pump be faulty or cushion defective, please 'Contact Seller' directly (other than Amazon Customer Service) from Amazon Buyer Central against your order for a replacement or refund.