The new MP-58 irons utilize revolutionary DUAL MUSCLE TITANIUMTM Technology. During the complex Grain Flow Forging process, a high-tech Titanium metal is forged into the outer muscle of the iron, which not only delivers the feel, workability and shape every MP player desires, but also provides increased playability especially in the long irons. The lightweight characteristics of the pure Titanium utilized in the MP-58s allow for an ideal amount of thickness behind the impact area to ensure the legendary soft, solid and consistent feel one expects from a Mizuno iron, while simultaneously providing a dramatic increase in perimeter weighting for enhanced playability. The MP-58 irons achieve the rare combination of a penetrating ball flight, increased MOI, and superior feel, all in the ultimate player's head shape. This perfect combination of playing characteristics is only attainable through the utilization of Mizuno's patented DUAL MUSCLE TITANIUMTM Technology!