The RecoilA(R) DART ESX takes our exclusive Recoil DART technology to a new level. After years of development, ESX design technology has been integrated with DART technology to increase tip stabilization for maximum shot consistency and improved accuracy. Features: Exclusive ESX design technology also increases launch and ball flight characteristics While DART technology optimizes hoop stiffness in the critical areas of the golf shaft. To achieve maximum distance, optimum hoop stiffness is designed into the energy transfer section of the shaft In the tip section, the hoop stiffness is increased to maintain feel while also stabilizing the tip section 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