Cobra Men's Fly Z+ Iron Set, Steel, Stiff, 3-PW, Right Hand Optimum Tuning Port: Position centered heel-to-toe and low in the club 8620 Soft Carbon Steel is softer than Stainless Steel Perimeter undercutting removes weight from the top-line and center of face to increase MOI Progressive CG Positioning delivers an optimized CG for each iron Progressive Set Design: Each Iron is specifically optimized to deliver a optimal trajectory and performance desired by the better player