With a balanced toe/heel carbon construction and central back weight, Mizuno's ST-Z driver encourages a low spinning, efficient straight ball flight.  Highly resilient Forged SAT2041 Beta-Ti Face: As a high strength Beta Ti, SAT2041 maintains its characteristics and resists micro fractures for longer than the commonly used 6-4 Ti. NEW Multi-thickness CORTECH Face: Refined to maximize the return from Mizuno's Beta Ti face. Ball speeds most noticeably improved low on the clubface. Quick Switch Adaptor: 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 club face. Z-Axis design for straight line flight: Balanced use of carbon composite on the sole and deep central sole weight are biased towards a straight-line flight and low spin efficiency. Wide, low footprint: With neutral visual lie angle 'Dense' or solid feedback: The majority of Mizuno's tour players expressed a preference for more dense feedback through impact. Mizuno's engineers spent a year finessing the sound to a more muted, powerful tone.