Originally $99, Gaiam's best-selling product of all time, the Ergonomic Balance Ball Chair, is now lowered to $69 during Gaiam's $30 off of orders over $100 promotion. The exercise ball chair includes a removable 52cm Balance Ball, an adjustable support bar, easy-glide casters, an air pump, and a desktop guide to get you moving. It's designed to strengthen core muscles and improving spinal alignment as you go about your daily office routine. The $30 is automatically taken off of the total at checkout. Shipping adds $16.95 and there is no sales tax (except CA, CO, OH).