The octagonal structure with a high-density co-polyester adds a phenomenal rotation to the ball and brings an exceptional spin. CONTROL As all our RPM strings, the RPM HURRICANE provides a great control to get accuracy in all your shots. A special low-density co-polyester offers more softness. Ideal for players looking for more tolerance. DURABILITY Co-polyester compound makes our RPM family very durable monofilaments. Ideal for heavy hitters who expect string performance over time. all our RPM strings, the RPM HURRICANE provides a great control to get accuracy in all your shots. A special low-density co-polyester offers more softness. Ideal for players looking for more tolerance.