Gaiam Classic Balance Ball Chair &ndash; Exercise Stability Yoga Ball Premium Ergonomic Chair for Home and Office Desk with Air Pump, Exercise Guide and Satisfaction Guarantee ALTERNATIVE DESK CHAIR: Created by leading health & fitness experts to improve overall well-being and provide an active outlet for having to sit for long periods of time 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 mind 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. Weight :13 pounds INCLUDES: Removable 52-centimeter 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 balls material to stretch to its final size. Inflate ball with air, let stand for 24 hours, deflate 50% then fill again to 52cm height.