Adhere to 15 minutes a day to keep fit, slim down, relax back muscles, and relieve hunchback. The outer ring is made of highly elastic TPE rubber, which has tear resistance and non-slip comfort. A firm grip keeps you balanced. Using unique TPE water wave non-slip texture, tear resistance, high density, softness, and high elasticity, the body is more stable. It has a high load-bearing capacity of 150 kg, high-strength compression without deformation. Its ergonomic arc bids farewell to the hunchback of the chest. The unique circular design is suitable for the spine arc, better assisting yoga, opening the shoulders and chest cavity, and relaxing the back muscles.