This round disc/cushion features one bumpy side and one smooth side.  Just add enough air so the individual's botton can wiggle ever so slightly.  Can help fulfill a childs need for movement and allows them to focus more.  Can be used while sitting, standing or lying on the floor, the dome shape and unevenness of the cushion add an element of instability, maximizing effort and enhancing results. Helpful for decreasing fidgeting and increasing awareness. Professional quality and made from tough, durable, latex-free PVC vinyl that is virtually indestructible.   Disc has a 15" diameter.