Tour Edge Men's Exotics XCG5 Project X Steel 4-PW 7-Piece Iron Set Complete set of XCG5 irons 4-iron through PW Variable face thickness technology allows for a 2.2mm thin face to maximize feel and produce exceptional distance 2 Additional tungsten sole weight helps lower the center of gravity and increase the irons stability at impact Progressive offset design produces ideal trajectory and distance control tailored specifically for each iron in the set. Deeper undercut cavity moves more weight to the rear outer edges of the head for maximum stability.