This seat is a gym ball with small integral rubber legs.It provides less support than the Fit Chairs, and will allow tipping back.It is more suitable for a child who has good understanding of their needs and is able to limit the movement that they produce when sitting on this ball.It can double up as a therapy ball for core stability work and is a good one to consider if you need a gym ball as well, as it could do both jobs for you and take up less space!