Gaiam's Balance Ball® Chair continues to be a favourite for many customers. It's revolutionary in that it offers health and fitness benefits while you sit at home or the office. The patented design combines comfort and ergonomic back support, all at an affordable price. Gaiam developed the BalanceBall Chair as an effective tool for strengthening core muscles and improving spinal alignment. Removable 52cm BalanceBall can be used for exercises on or off the chair. Easy assembly required.