The foundation shank is a waddington shank. If you're unfamiliar with a waddington shanks ("WS"), they look like this:
Let me just say, this fly looks killer in the water and is a proven fish getter too. The negative is that it is heavy. The fly is not too much for a 7 or 8 weight but in this size it would be a bear to cast on a 6 weight. That being said, the fly is 5+ inches long so you are going after the big fish of the bunch.