Highest Quality, Burst Resistant Classic Exercise Ball Chair by Fitter for Sitting, Stretching and Strengthening. At work or in the gym, Exercise Balls help you to improve core stability, strength, balance and awareness. While at your desk, sit on a Ball Chair to engage in Active Sitting. When exercising, incorporate a ball into your stretching and weight programs to improve coordination and stability. Keep kids sitting active on a ball while watching TV or playing video games. An Exercise Ball is even great for relieving discomfort before, during and after labor. • Burst resistant up to 285 lbs. (130kg) • Static load rated to 1,000 lbs. (455kg).