JPX 923 Hot Metal Pro introduces all-new Nickel Chromoly - a new material that increases ball speed. Its 35% stronger than the original Hot Metal material, allowing Mizuno to create a thinner topline and faster ball speed. A new V-Chassis design delivers a more satisfying vibration at impact for improved sound and feel. Seamless cup face construction moves CG lower in the face for higher launch and greater stopping power. The thinnest part of the sole is extended 18% wider to expand consistent ball speed across the face. The non-reflective, Chrome plated finishing reduces glare from the sun.