Callaway X Forged UT Utility Golf Driving Iron boxing21 two piece Pebax elastomer insert consisting two piece Pebax elastomer insert consisting of a soft front with PLD inspired shallow grooves and a firmer back to ensure the optimal combination of feel and distance control Combined with an Zoom Air unit for even more cushioning making this one of the comfiest shoes on the market A longer blade length and a wider sole versus a traditional long iron provide forgiveness and control Forged from a 1025 mild carbon steel and with hollow body construction which is combined with Callaway's proprietary urethane microspheres to create pure feel and an extremely soft feel