Mizuno ST-Z Golf Driver Low Spin Efficiency From An Ultra-Stable Frame. Mizuno’s ST-Z Golf Driver has a toe-heel carbon composite construction balanced with deep central back weighting for an efficient spin and a straight-line ball flight. Mizuno has utilised their forged SAT2041 BETA Ti Face as it enters a second generation, in generating potent ball speed for consistent performance on every ball hit. The highly resilient face which is 17% thicker than the next model, continues to respond and maintain character to resist fracturing and extend lifespan. ST-Z CORTEC across the face, maximises return, and as a result ball speeds are noticeably improved low across the clubface. To improve on the ST-Z, Mizuno also incorporated denser feedback at impact, at the request of tour players. It has taken engineers years to finesse the sound, but they have created a more muted and powerful tone in the latest of ranges. Quick Switch Adjustability 4 degrees of loft adjustability to fine-tune look and trajectory. Optimized Wave Sole Plate Delivers an additional contribution to ball speed – low from the clubface. Z-Axis design for straight-line flight Balanced use of carbon composite on the sole and deep central sole weight is biased towards a straight-line flight and low spin efficiency. Wide, low footprint With neutral visual lie angle.