This ball chair includes wheels that can lock in place. It is an exciting way to sit, while promoting healthy posture, and proper spinal alignment. The chair combines the benefits of a therapy / swiss ball with the convenience of a real chair to hold the ball in place. It is also recommended by educators for children that have trouble sitting still in the classroom. The ball chair allows them to wiggle, and move, while staying seated. The Ball Chair is 15" - 15.5" off the ground, and is recommended for children between ages 5 - 7, depending on the child's size.