Callaway Golf RAZR X HL Irons Set RAZR TechnologyRAZR Technology shifts the center of gravity lower and deeper by redistributing weight in the back cavity; providing the power and forgiveness of a wide-sole iron with the precision and playability of a thin-sole iron. Solid Impact SoleCreates smooth turf interaction for better distance, accuracy and distance. VFT Power SystemFully integrated clubface/undercut cavity system that enables engineers to precisely position the CG and engineer the face of each individual iron to maximize ball speed. Multi-Material Medallion Constructed of aluminum and thermoplastic polyurethane, it fine-tunes sound and enhances feel off the clubface.