With a blend of long-game distance and greenside control, the new Z-STAR DIAMOND also delivers the unique benefit of increased spin on long and mid Iron shots. NEW Thin, Premium Urethane Cover with Biomass Every Z-STAR Series golf ball features an extra thin, premium urethane cover for tour-caliber green side spin, feel and control. Srixon's latest covers are also made with Biomass-a durable, plant-derived material requiring fewer carbon emissions to manufacture. It's Srixon's signature unbeatable performance and feel, plus a step toward reducing environmental impact. NEW FastLayer DG Core 2.0 A newly formulated core starts soft in the center and gradually becomes firm around its edge, giving high-speed players exceptional feel, optimized Iron spin, and plenty of ball speed for maximum distance. Spin Skin+ Coating A durable coating, Spin Skin+ digs deep into Wedge and Iron grooves, maximizing spin for better control and stopping power, while also improving the cover's resistance to dirt and grime. 338 Speed Dimple Pattern Less drag and more lift boosts overall distance and flies straight, even in the toughest wind conditions.