ST-G 440 Driver Featuring a player-preferred 440cc pear-shaped with a deeper face, the new Mizuno ST-G Driver delivers exceptionally low spin. Mizuno's CORTECH Chamber transforms the ST-G into a powerhouse. Strategically located close to the face, the chamber encases a dense stainless steel weight with elastomeric TPU, creating an additional energy source that generates explosive ball speeds, distance, and reduced spin rates. While smaller, reduced spin offerings are inherently less forgiving th