Oursmile Professional Strength Swiss Ball for Office, Exercise, Stability and Fitness 55cm, 65cm, 75cm,Size Fitness Balls Available. The ultimate in professional-strength exercise antiburst balls Ideal for any individual looking to burn calories while at work or while working in front of a computer. Shown in clinical studies to reduce back pain; while improving posture Slim down, tone up, strengthen core muscles and add variety and challenge to your personal or gym workout. Grey color blends in with any office environment, and rapid-action foot pump makes inflating it a breeze.