Original set of Jack Nicklaus Muirfield 20th Anniversary irons. These limited edition irons were produced in the late 1980s. Many golfers believe that this set is one of the finest set of blades every produced. It was a modern blade take on an earlier muscle back design, and the result was a special set of irons. This set is unused and in excellent condition. 3 clubs still have plastic on the face. 11 irons total, 1-PW, SW. Dynamic Gold s300 shafts.