Valve: Elastomer A Don Chadwick design Dome: Thermophlastic vulcanizate A fun sitting solution, Ballo is a multipurpose stool that is ideal for a wide range of environments. Designed by Don Chadwick, it reinvents the exercise ball with a design that is appropriate for workplace settings. Promoting short-term, active sitting, Ballo encourages low intensity physical activity. Top Cone: Polypropylene Screws: Steel Center Column: Polypropylene Height: 24.5” Diameter: 17.8” Weight: 13.5 lbs.