The Dynamic Seating Cushion is a wonderful tool to work on balance and postural training. The inflatable disk features a smooth surface on one side and a softly molded circular pattern on the other. Ideal for clients of all ages and is particularly effective with individuals with Autism and ADD who have a difficult time sitting still in classrooms. This seating cushion not only provides sensory and tactile input, but helps individuals focus. The cushion has a 15 inch diameter.