Srixon Z-Star XV Golf Balls 2021 The Srixon Z-Star XV Golf Balls are manufactured to offer you maximum distance from their new reformulated inner core. This new inner core boosts overall resiliency, allowing for a faster snap off the clubface, allowing for extreme distance and fast ball speeds. FASTLAYER CORE Featuring Srixon's FastLayer Core, you are provided with greater ball speeds and a fantastic feel. This allows you to play with confidence and add distance to your game. URETHANE COVER Featuring an extra thin, thermoplastic urethane cover, providing you with better spin and control. SPIN SKIN COATING Srixon has added an extra Spin Skin coating to provide you with even more spin and control. This additional layer is extremely thin, but it uses Slide-Ring Material to increase friction and maximise spin on chips and pitches. 338 SPEED DIMPLE PATTERN Featuring new, deeper dimensions to provide a penetrating launch. After impact and launch, the dimples generate lift, driving the ball upward and maximising glide distance during descent.