Callaway Golf Big Bertha 08 Irons Set, Set of 8 Clubs (3-PW) Fully integrated set design provides seamless performance progression with consistent distance separation and optimal trajectories New i-brids blend the control and accuracy of irons with the forgiveness, distance and versatility of hybrids Super game-improvement mid and short irons deliver the ultimate in forgiveness with increased offset Callaway golf core technologies include extreme notch weighting , VFT, S2H2 and a 360-degree undercut channel The New modified Tru-Bore , an advanced version of the original Tru-Bore design Incorporated a polycarbonate tip plug at the end of the shaft that dampens vibration for enhanced feel and performance