The Mizuno Pro Irons are the result of a longstanding connection between Mizuno's club engineers and the legendary Grain Flow Forging plant in Hiroshima, Japan. Every fraction of a millimeter and subtle curve has been meticulously considered, shaping the future of golf club technology. Key Features of the Mizuno Pro 243 / Tour Speed: Grain Flow Forged HD in Hiroshima, Japan 4120 Chromoly with Flow Microslot (4-7 iron) Soft Copper Underlay for sensational feel Harmonic Impact Technology for a soft muscle-back feel Wrap Around Sole Grind for improved turf interaction Exceptionally compact players' profile Increased bounce angle for enhanced performance Full Satin Brush finish Available 4-GW / RH only