Brand NEW! Wilson's Duo Power is a hybrid string that blends NXT Power with ALU Power for an explosive string bed second to none. For ideal playability, reduce tension on ALU Power at least 10%. Either string can be installed in the mains for superior power and performance. Blend of NXT Power ALU Power Ultimate power Reduce tension on ALU Power at least 10% for ideal playability Racket String Category Power, Hybrid String Gauge 16L (1.25MM), 16G (1.30MM) String Material Poly-Ether-Ether, PU String Type Hybrid Color Silver Pack Size Set - All international buyers are responsible for all tax, duties and/or customs fees