Northwave GT3 Road Shoes - Anthra/RefMorph Carbon 12 AAS sole with full carbon insert in the pedal area with a stiffness index of 12. 0. The exclusive Anatomical Arch Support made of TPU,allows the shoe to perfectly shape on the bow arch,making it the ideal sole for any type of foot. Speedplay adapter compatible for the lowest stack height between foot and pedal. Made with the patented XFrame 2 construction,the upper transfers every watt of power while providing the snuggest, even fit