The DFC System is the recent innovation developed in the TCX Research and Development Center, with the aim of offering an excellent balance between flexibility and protection. The structure consists of a special polyurethane compound that facilitates the natural flexion of the foot / leg back and forth, preventing the risk of torsion of the joint. The system features a polyurethane skeleton, firmly connected to the boot, through two hidden screws, positioned in the heel area, at the height of the malleoli. At the back, the system is equipped with two flaps that slide inside special "safety lock" pockets to allow controlled rear flexibility up to 13 ã, thus preventing the risk of hyperextension of the joint. The polyurethane skeleton has a thin profile and a design designed to adhere perfectly to the quarter; the inside of the boot has a smooth surface, free of grip points and able to offer an excellent level of grip to the bike frame. DFC is designed to give the boot a high level of p