Wilson NXT 16 Tennis String : WRZ942700 Featuring proprietary Xycro Micro-Fibers impregnated with PU for enhanced comfort and power, NXT is the world's most popular multifilament string. Sporting a larger sweet spot than traditional synthetic gut string and a fraction of its shock, NXT has stood the test of time for good reason. For installation, handly gently and avoid over-clamping and crimping. Wilson NXT 16 Tennis String | Christy Sports