Uses a gyroscope mechanism with eccentricity and constant inertia. Power is generated by wrist rotation, requiring no battery or external power source. The faster the wrist movement, the greater the kinetic energy. Helps improve grip strength, endurance, wrist strength, and arm strength. Designed to support blood circulation, strengthen wrist ligaments, and help reduce the risk of sports-related injuries. Suitable for individuals involved in sports such as golf, bowling, baseball, basketball, volleyball, handball, tennis, badminton, and kendo, where wrist strength and control are important. Can also benefit those engaged in activities like computer typing or piano playing by supporting wrist health. Ideal for individuals seeking regular wrist exercise and those in rehabilitation to help prevent muscle stiffness. Compact and portable design generates high kinetic energy. Suitable for all age groups and can be used anytime, anywhere—whether at home, in the office, during travel, or while watching TV. No space limitations required.