Gaiam Classic Backless Balance Ball Chair, Charcoal | 52cm (20.5 inch) | Active Seating for Office & Home

• BOOST ENERGY LEVELS: Featuring the same yoga ball as the exercise guide, this chair helps to boost energy levels and increase productivity with an active body and a focused and engaged min
• RECOMMENDED USER HEIGHT: Designed for users 5' to 5'11" tall and fits most standard-height desks. For a taller chair, add 2 inches with Gaiam's compatible leg extenders, sold separately. 300-pound weight capacity.
• INCLUDES: Removable 52-centimeter charcoal exercise ball, an air pump, an adjustable metal support bar, 4 easy-glide casters (2 back wheels lockable), and a desktop exercise guide to stay active
• INFLATION INSTRUCTIONS: It may be necessary to re-inflate the ball after initial inflation to allow the ball’s material to stretch to its final size. Inflate ball with air, let stand for 24 hours, deflate 50% then fill again to 52cm height.

• Attach the 4 easy-glide caster wheels to the base. Insert the adjustable metal support bar into the designated slots on the base for added stability. — Assemble the Base
• Use the included air pump to inflate the 52cm exercise ball. It may require re-inflation after 24 hours to allow the material to stretch fully to its intended size. — Inflate the Ball
• Place the inflated ball securely into the chair base. Sit on the ball, ensuring your feet are flat on the floor and your knees are at a 90-degree angle. Engage your core. — Position and Sit
• Refer to the included desktop exercise guide to perform simple movements that further activate your core and improve circulation while seated throughout the day. — Engage with Exercises

Typical situations where Gaiam Classic Backless Balance Ball Chair helps — illustrative scenarios, not customer reviews.