PRO Irons feature the industry-leading proprietary High-Density Composite Core (HDCC) which produces dialed-in swing weights at steel length. All PRO Irons come in 2i length “one length blanks” which will give a player the option to soft or hard step to reach in-between flexes. HDCC (high density composite core) technology is proprietary and allows clubs to be achieve steel swing weights and steel length, something no other graphite shaft can accomplish. HDCC material is added in the mid-to-tip section of our iron shafts to balance the weight. HDCC is 62% more dense than standard modulus material used in composition of graphite shafts. Premium materials ensure better consistency than steel. Lighter weights allow for more club speed and premium stable materials ensure control. HDCC material significantly reduces vibration compared to steel to allow for softer feel.