Srixon ZX MK II FairwayRebound Frames Dual Flex Zones focus more energy into the golf ball at impact, creating a purer energy transfer that instantaneously increases ball speed and distance on every strike. A complex series of ridges and latticework provides the structural integrity necessary to feature a remarkably thin titanium crown and to place discretionary mass where it best suits each ZX Mk II Drivers ideal launch and spin characteristics.