The NEW (2) Tecnifibre PU 400 X-ONE Biphase tennis string is a high-quality non-geared string made in France by the renowned brand Tecnifibre. With a 17 gauge 1.24mm diameter, this red string offers a perfect balance of power and control for tennis players. The X-ONE Biphase model is designed for optimal performance on the court, making it a popular choice among players looking to enhance their game with a reliable and durable string.