Stiff Flex. The ZX MKII Utility Iron returns as a powerful long iron replacement desired by Tour pros for explosiveness, control and forgiveness in a bladelike design. MainFrame technology features a variable thickness pattern of grooves and channels milled into the backside of the face to maximize flex at impact. The forged face is very strong yet light to increase flex, speed and distance, combined with a forged carbon steel body to dampen vibrations for a softer, forged iron feel. The ZX is constructed with Srixon's widest soles and minimal offset, as well as an appealing look at address for a sleek look preferred by Tour pros. Sole notches on the heel and toe reduce drag and improve turf interaction to provide consistent speed and versatility without sacrificing forgiveness.