Head DesignThe heads of the Nike Golf Vapor Pro Combo irons are forged and milled from 1025 carbon steel in concert with the RZN cavity for advanced and consistent ball striking. The midsize profile of these irons change from longer blade, lower profile long irons, through to traditional shaped short irons.Progressive Sole WidthsThe Nike Golf Vapor Pro Combo Irons feature progressive sole widths with a beveled leading edge offering you, the golfer, playability and heightened flexibility while machine milled X3X grooves generate huge spin control and shot-to-shot reliability.These Nike Golf irons feature:Progressive SetThe Vapor Irons are made up with the following combination of head designs. The long irons are crafted around the RZN cavity (4, 5, 6, 7) and the short irons with a extremely playable muscle cavity (8, 9, P) for the combination of stability and shot-shaping playability. The long irons even utilise ultra-fast Spring Steel faces (4-7) which further increase ball speed.Conclusion:These fantastic Nike Golf Vapor Pro Combo Irons offer the player a modern looking muscle design which balances the CG in the centre of the face for maximum ball speed, second to none consistency and the cleanest of feel.