Cobra 3400 I/HX Irons. Cobra's most technical irons ever, the 3400 I/XH irons feature a transition design, which morphs from a hollow back (3-7 irons) to a cavity back design (8-LW irons). Aimed at higher handicappers, this transition gives optimal weight distribution for that extra-high launch and massive Sweet Zone. The advanced undercut design pushes weight low and back for a deep centre of gravity and high moment of inertia - resulting in higher shots that fly further. Made from high quality 431 Stainless Steel, Cobra 3400 I/HX Irons are perfect for the golfer who wants the perfect balance of accuracy, forgiveness and distance. The Urethane insert dampens vibration for superior feel while a 'Super-sized' sweet zone across the whole club face provides exceptional forgiveness on off centre strikes.