MSRP $24.95
MAP $15

X-One Biphase is a multifilament string constructed using a new variation of the tried-and-true Tecnifibre process. According to Tecnifibre, X-One Biphase combines H2C (High Heat Capacity) microfilaments for power and feel, with NRG microfilaments for dynamic response. These microfilaments go through a chemical "trimerization" process to increase cohesion when dipped into polyurethane for bonding, and external protection against wear and notching. As with other Tecnifibre strings, the polyurethane also absorbs vibration and reduces shock. Tecnifibre tells us that its patented Biphase process extends string life by 20 percent and increases spin performance.

X-One Biphase earned the highest Power rating of any string play tested by Racquet Sports Industry, dethroning Tecnifibre 515 16L and moving Tecnifibre NRG2 SPL 17 from second place to third highest of all time. They also loved the Comfort, awarding X-One Biphase our best-ever rating of all the strings we've tested.

In addition, RSI rated X-One Biphase third place overall both in Playability and in Spin Potential (the Biphase process in action?), and fourth place overall in Touch/Feel. For good measure, they also rated it well above average in Control. The average score was good enough to vault X-One Biphase into fourth place of all the strings we've tested.