The Fitness Mad 7 Inch Exer-Soft Ball is perfect for use in all kinds of floor exercises to make your workout more interesting, to build strength and aid concentration. Place it between your knees, hands or arms to introduce resistance training into your routine. Alternatively, use it to help with concentration and relaxation or use it to help with your pelvic floor exercises. The ball is 7 inches in diameter and is anti-slip to help you get a good grip. This exercise ball has been factory tested and found to be burst-resistant at 100kg. The soft ball is sold in different sizes (7, 9 or 12 inches), so finding the size for your own personal preference could not be easier.