Callaway Golf FT i-brid Irons Set, Set of 5 Clubs (6-PW) Fusion Technology enables weight to be shifted for optimal performance through the use of a lightweight titanium body , Tunite weighting in the sole, and a TPU SenSert. 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 provide the ultimate in forgiveness with increased offset, a large effective hitting area and wide sole. TPU SenSert decreases vibration for an incredibly solid feel. The modified Tru-Bore, a advanced version of the original Tru-Bore design, incorporates a polycarbonate tip plug at the end of the shaft that dampens vibration for enhanced feel and performance.