Tour Edge EX-1 Iron Set 3-PW with Nippon Steel Shafts : The Tour Edge EX-1 Irons combine a traditional, blade appearance with a low CG (center of gravity) sole and a technologically superior hollow box cavity. For the first time, a tungsten sole can be welded to a 17-4 stainless head. No need for press fitting. This unique form of tungsten allows for a larger, more engineered sole in which the tungsten can be cast into any shape. It also repositions nearly 40 grams of the head s total weight (100 grams) toward the heel and toe and back away from the face. The fusion of grace and beauty, this design allows the sole width to be thinned for a classical blade like look, better workability, a lower CG, and the superior forgiveness you expect from a hybrid.