Callaway big bertha irons steelthese new callaway golf big bertha irons can make you up to 2 clubs longer for the first time callaway are putting the cup 360 face technology they use in fairway woods into their ironsup to 2 club longer distanceup to ldquo2 clubs longerrdquo is for real higher ball speed all across the face comes from the same 360 face cup technology we put in fairway woods combined with an internal standing wave this is the hottest iron wersquove