This seat cushion is not air filled, but was designed for the "antsy" student, the student who always sits on the edge of the seat or the student that sits on a corner of the chair with his/her feet out in the aisle. It helps to center the hips, by providing a small padded, physical well. The physical barrier on three sides help orient the child to where his body is in space. Made of extra tough, durable material and stuffed with a non-food substance. A large non-slip mat is sewn on the bottom to eliminate sliding. Available in 2 sizes and is hand washable.