Cobra Amp Iron Set Advanced Material Placement: Multi-alloy design strategically positions weight to provide explosive long irons and consistent short irons. Full cavity TPU layer dampens vibration and provides exceptional feel. E9 Face Technology: features a progressive face and cavity design optimizing distance, feel and forgiveness in each individual iron. New V-Skid Sole Design: Promotes consistent distance and accuracy with a versatile mid-width sole that narrows in the toe and heel.