Srixon I-403 Irons. Tungsten Nickel sole weighting and variable back weighting through the set optimize centre of gravity for higher trajectory. Extremely soft 255 stainless steel provides great feel and response. The sweet spot area "Cavity Flow Design" positions the back cavities towards the toe in the long irons, towards the centre in the middle irons, and towards the heel in the short irons. Srixon has adjusted the sweetspot for optimum accuracy. Variable hosel lengths and varied back weighting position further optimize the CG point so the long irons area easy to square and get up in the air, while the short irons have the ideal scoring trajectory.