The Mizuno Pro S-1 irons represent the pinnacle of refined craftsmanship and elite performance, embodying the heritage of Mizuno's forging expertise while catering to the demands of today's golfers. Grain Flow Forged HD: One-piece Grain Flow Forged HD from 1025E Pure Select mile carbon steel at Mizuno's iconic facility in Hiroshima, Japan. Where Mizuno irons have been produced since 1968. Harmonic Impact Technology: Fine tuned head geometry delivers ideal impact feel and feedback Back Milling: CNC milled from the sole up creating a larger area of minimum face thickness for consistently increased ball speeds. V-Chassis: Engineered via Mizuno's Harmonic Impact Technology, the V-Chassis allows the top line to be thinner without sacrificing feel and sound. White Satin Brush Finish: A modern elegant, yet durable non-glare finish Triple Cut Sole : Beveled trailing edge and blunted leading edge ensures clean turf interaction for solid contact. 1025E Pure Select : Six times tighter tolerance than industry standard for greater purity. Copper Underlay: Thin copper layer beneath a nickel chrome to provide a further enhanced impact feel Refined Topline: Mass taken from the toe portion and a lower hosel blend creates a smaller profile without loss of effective hitting area. Compact Player's Profile: Dramatically reduced topline and blade length throughout the set.