This large 60 cm, (23 1/2 in.) air cushion, or as we call it, "Big Blue," is studied with bumps on one side and is more gently textured on the other side. Use it on the floor sitting, kneeling or standing to challenge trunk and leg muscles and improve balance. Two children at the same time will have loads of fun trying to stay on their feet as they march around. And, it is a favorite spot for cushiony, wobbly, tactile exploration by infants and toddlers.