Wilson Duo Power Hybrid Tennis String - ALU and NXT Power 16 WRZ949710 Duo Power is the perfect hybrid for the player who wants outstanding playability. It includes Luxilon ALU Power 16L, one of the most iconic co-polyester strings ever made. This string will give you an outstanding combination of control, spin and durability. The other string is NXT Power 16, one of the softest and most responsive multifilaments on the market. Taken together, this hybrid delivers a "best of class " combination of spin, power, comfort and precision. Blend of NXT Power & ALU Power Ultimate power Reduce tension on ALU Power at least 10% for ideal playability Wilson Duo Power ALU and NXT Power 16 Tennis String | Christy Sports