Wilson's Duo Control is a hybrid string that blends NXT Control with Luxilon 4G Rough for a string bed optimized for spin, precision and tension maintenance. For ideal playability, reduce tension on Luxilon 4G Rough at least 10%. Either string can be installed in the mains for superior control and performance. FEATURES: Blend of NXT Control & Luxilon 4G Rough Ultimate control Reduce tension on Luxilon 4G Rough at least 10% for ideal playability MATERIAL: Poly-Ether-Ether, PU COLOR: Gold Wilson Tennis String WRZ949720