Single shaft BB 703 The roller is made of durable plastic, and the wheels are covered with non-slip material. The roller handles are mounted on a steel core. It is used to strengthen muscles throughout the body. Product description: it is made of durable plastics, the wheels are covered with anti-slip material the roller handles are mounted on a steel core Application: it is a very simple device that takes up little space Its ease of use makes it quite popular and widely used both in gyms and at home. It is primarily used to strengthen the abdominal muscles, but when exercising with this device the entire body is strengthened