Add extreme distance with the Callaway Big Bertha Hybrids Features: A more flexible iron face helps the ball jump off the club with some serious ball speed behind it. It adds to the forgiveness too - the ball speed is high wherever you hit it on the face. A more flexible iron face helps the ball jump off the club with some serious ball speed behind it. It adds to the forgiveness too - the ball speed is high wherever you hit it on the face. Your shots will launch higher and fly straighter. Hollow