Full set of 7 shafts for your 4-PW. Catalyst is the next step in graphite iron design. Featuring our new Iso-6 material technology, Catalyst is engineered to replicate steel alloy properties over 100% better than traditional graphite laminates. This allows for an extremely stable shaft that maximizes constancy and distance control while providing the benefits of a graphite body design. Catalyst also features a reinforced tip section which, unlike traditional graphite, delivers torsional resistance comparable to that of steel?improving stability during turf interaction for better impact on less than perfect shots. ISO-6 is a revolutionary technology that bridges the gap between what a steel shaft is and what a graphite shaft can be. Traditional graphite laminates are only 35% as symmetrical as steel. Through advanced material modeling and analysis, Project X engineers constructed a new laminate design to eliminate weak spots found in graphite iron shafts due to the lack of symmetry. With ISO-6 being 75% as symmetrical as steel (over 100% better than traditional graphite laminates), graphite iron shafts made with ISO-6 provide superior accuracy in comparison to the competitors’ shafts.