The Wilson Pro Tour BLX is a new update to the control-oriented K Pro Tour, and is used by Juan Martin del Potro. Wilson introduces the use of Basalt fiber (BLX) technology for improved feel and frame feedback, continuing to feature classic feel in the same tradition as the previous-generation K Pro Tour.The Pro Tour BLX retains a classic 'tweener design, now with a denser 18x20 string pattern (delPo's preference), 11.6 oz. strung weight and 24mm wide beam. Added control and feel are present thanks to the 96 sq. in. headsize, 18x20 string pattern, and traditional leather grip. BLX builds upon the very popular K Factor design, offering a refinement of Wilson frame technology that provides the ultimate in feel and performance.