Unique child friendly seats offer the advantage of a traditional wiggle seat, but with a lot more fun. kids stay calm and focused while sitting on this fun shaped sensory cushion as the movement that the seat allows gives them an outlet for excess energy in the classroom, during meals and at homework time. It is effective on a chair, bench, directly on the floors and even outside. 13”/33cm diameter is a great fit for a kid’s seating. Comes inflated and includes easy-inflation pump. Purple.