TECNIFIBRE X-ONE BIPHASE TENNIS STRING SET 1.30mmThe X ONE BIPHASE string is the best performing string in this range on the three criteria of playability, durability and integrity. The particularity of this range is to present a wear indicator, which allows the player to change the string before the complete breakage. This indicator is manifested by the significant fraying of the string at the point of impact of the ball. Tecnifibre is the leading brand in strings and has built its success on the