Babolat Xcel Tennis String Multifilament Synthetic. Xcel provides the ultimate in comfort and durability. It"s remarkable durability is due to the large number of Polyamide fibers that are adhered perfectly together. The increased elasticity of the fibers also provide optimal comfort and better tension maintenance. This string is the ideal partner for players looking for the best combination of comfort and durability. Length: 40 feet / 12 meters Gauge: 16 gauge / 1.30mm 17gauge / 1.25mm Color: Black