It is an air-filled and burst-proof ball with ABS® Anti-Burst material. The material is odourless and very durable up to 1000 kg (ABS burst proof guarantee 170 kg, for 75 cm to 120 kg). The product is latex-free, consists of 100% recyclable plastic and is manufactured in Germany. What does it do? Strengthens especially the abdominal, back and trunk muscles through safe, effective and dynamic back and stability training. Can train back musculature by sitting upright and in motion. Improves coordination and balance. How does it work? While sitting on the ball, an upright posture is automatically adopted. At the same time, the pelvic floor, abdominal and back muscles are involuntarily used again and again to balance the body. Instructions with concrete exercise suggestions are included in the product packaging. In the event of damage by objects such as sharp edges, needles, glass splinters, scissors, etc., the material of the ball skin prevents it from tearing open abruptly. The air escapes only slowly through the hole. Bursting is impossible and injuries due to an unexpected fall are avoided. Characteristics of the original anti-burst material: Due to the special anti-burst material, the shape of the ball may change during use. This does not affect the effect while sitting or the movement during exercises. The decisive factor is the dynamics and the safety system of the ball, not its circular nature. Approximately ten minutes after leaving the ABS® Ball, the ball regains its round shape due to the restoring force of the material. Due to the packaging process, an ABS® ball still has some wrinkles after inflation. Due to the special safety material, these wrinkles may also be permanently visible on an inflated ABS® Ball. This in no way affects the functionality or safety.