Gamma Asterisk 17G Tennis String, Natural The newest high-tech multifilament string, offers superior playing characteristics with the added benefit not found in most multifilament strings, superb tension maintenance. Features a unique high energy core consisting of an Asterisk* multifilament center encased by a high tenacity polyamide matrix. Holds tension longer and offers superior playability longer. Crisp vibration-free feel for ultimate comfort. Available in Natural.