Ergonomically designed, sturdy, and comfortable, the Cando Fitness Ball Chair is ideal for use at the office, or at home. While seated, the instability forces you to use your muscles ? strengthening your core, and improving your posture. The perfect combination of stability ball and chair, the Cando Fitness Ball Chair comes with a metal frame and a removable/adjustable back. This chair has arms, and is best for users that are 5? 0? - 5? 11?.