The M4 returns, featuring Twist Face technology with a new Hammerhead Slot and Geocoustic sole design for straight distance and a large sweet spot. Twist Face brings revolutionary face curvature together with a corrective face angle on off-center hits. This construction reduces side spin and delivers straighter shots, with more loft in the high-toe and less loft in the low-heel for consistent spin. A Hammerhead Slot allows for a lighter, more flexible face to create a larger sweet spot. The center slot portion enhances ball speed low on the face while eliminating unwanted spin for more distance. Geocoustic technology reduces sole volume and enables a larger, more forgiving face.