The Callaway Big Bertha irons are an updated design of the 1996 model. These irons have a wide sole that is rounded to aid set up and prevent digging into the turf. The cavity allows the Center of Gravity to be lower as well as more weight to be moved to the perimeter for added forgiveness. The bore-thru hosel adds even more stability at impact to keep shots on-line even if they are struck off-center.