HEAD Lynx Edge Tennis String Blue is an innovative string that features a new co-polymer mixture to give advanced players more bite on the ball. This heptagon (7-sided) shaped string is perfect for players looking add more spin to their game without compromising on durability.   Composition: Co-Polymer Monofilament Length: 40 ft (12.2 m) Gauge: 17G (1.25 mm) Color: Light Blue