The Wiggle Cushion is a perfect solution for children who have a tough time sitting still. The Wiggle Cushion is a cross between a ball chair and a seat cushion. You can inflate the Wiggle Cushion to the max to stimulate balance and core work, or deflate to use as a seat cushion which encourages movement. One side of the cushion is a smooth surface, the other side has slightly raised "bumps." You can choose between receiving tactile input or sitting on a smooth surface. Great alternative to a ball chair that can be used in school, home, clinic or travel. Use to teach balance. Use to have kids stand on during standing circle-time. For ages 3 - teen. Inflates in seconds. Measures 13" diameter.