Yonex PolyTour Force 17 / 1.20 Tennis String BlackYonex PolyTour Force 17 1. 20 Tennis String 1 Set Power and Durability Engineered for durability and stability, the Yonex PolyTour Force 17 delivers controlled power with a firm, solid response that advanced players can trust. Its thicker polyester monofilament construction enhances tension retention, helping maintain consistent performance during long, high intensity rallies. Designed for players who generate heavy pace, it provides a stable,