The Movin' Sit Jr. Air Cushion is an inflatable dynamic cushion which activates intrinsic trunk muscles to support the spine. The wedge shape encourages a seated posture with a forward pelvic position. It can also be used upright in any chair as a back support or on the floor. Adjust inflation to comfort level. 10" x 10" cushion fits perfectly in elementary school desk and other chairs. Especially designed for children.