St-z 220 driver. 20g stainless steel weight optimally placed below the sole surface and extreme back and heel side for a large moi boost and cg for higher launch. Designed for neutral trajectory with a further back positioned cog along the neutral z axis for increased launch stability on high and low impacts. 460cc volume that is pushed slightly lower to the ground for higher launch and mid spin performance. At address the st-z lines up square to slightly open in the standard setting. Multi-thickness cortech face that is refined to maximize the return from the beta ti face and improve ball speeds on shots low on the clubface. Forged sat2041 beta ti face composed of super alloy titanium, vanadium (20%), aluminum (4%), and tin (1%) is 17% stronger than commercial 6-4 titanium and provides enhanced cor to ct performance. Hit tuned impact sound ribs strategically placed in the club tune the sound to the appropriate frequency and sound pressure. 4 degrees of quick switch loft adjustability let you fine-tune the address look and trajectory.