The Tecnifibre X-One Biphase 1.30 tennis string has been designed to provide increased durability, superior power & control. This multifilament string provides good tension maintenance & a gut-like feel. It is composed of High Heat Capacity (H2C) fibres that provide superior feel & power, & Polyurethane fibres for shock absorption. The string utilises the new Biphase process that increases durability by up to 20%. The Tecnifibre X-One Biphase has a 16 (1.30mm) gauge & is available in a 12.2m (40ft.) set.