The RecoilA(R) DART HDC has been designed after years of research and testing to precisely optimize shaft hoop stiffness in the critical areas of the golf shaft. High Density Carbon is low resin / high density carbon fiber that maximizes the performance benefits of the carbon fiber and achieves the best possible feel. Features: DART Technology is utilized to achieve maximum distance through optimum hoop stiffness designed into the energy transfer section of the shaft While in the tip section, the hoop stiffness is increased to maintain feel while also stabilizing the shaft tip for maximum consistency and optimum ball flight Additionally, Dual Action Recoil TechnologyA(R) eliminates inconsistent areas in the golf shaft for precise feel without the a ~clunky dead feela (TM) of other iron shafts