3 - 8 years. Specially designed wiggle seats for young children help calm and focus those who have a hard time sitting still. Allow children to quietly move while working, enabling them to focus, stay on task and be more productive. Flexible nubs on one side and small bumps on the other can easily be felt giving a choice for just the right amount of tactile stimulation. Ergonomic disc causes the body to stabilize itself improving posture. Easy-inflation pump is included and firmness can be customized to each child's needs. Effective on chairs, benches, or directly on floors. 10.75" diameter comfortably fits a young child.