Features and Benefits of the Ping i-Series Irons:The first Ping irons made with 431 stainless steel.Engineers relied on the material's high strength-to-weight ratio and softer feel to create a head design that delivers workability and trajectory control with the right amount of forgiveness.Lengths and lofts are optimized to increase distance with proper gapping, resulting in a clean, players-style iron with a high MOI that offers wide appeal.