The Tecnifibre X-One Biphase 1.24 tennis string provides maximum durability, power & control. It offers good tension maintenance & a gut-like feel. The string comprises of High Heat Capacity (H2C) fibres that ensure superb feel & power, & Polyurethane fibres that minimize shock & enhance comfort. The string utilises the new Biphase process that provides up to 20% extra dupability. The Tecnifibre X-One Biphase has a 1.24mm gauge & is available in a 12.2m (40ft.) set.