• Exercise Gym Ball can be easily incorporated into a wide range of exercises to develop your core, balance and posture
• Designed to constantly engage your entire core as your muscles work overtime to help you maintain your balance
• Durable anti-burst PVC material with anti-slip rings around its perimeter to stop it sliding around when you're exercising
• Gym ball comes in 4 sizes with hand pump, measuring tape, stopper plug (including spare plug) and plug removal tool
• Can also be used as a desk chair to improve your core stability, develop your posture and reduce stress on the spine