Product descriptionTecnica say - The Mach 1 delivers a high-performance skiing experience. Every model is designed with an anatomical shape, providing best-in-class out-of-the-box fit.C.A.S Shell, anatomical shape that matches the foot shape allows for better out-of-the-box fit. C.A.S liner, anatomically shaped for optimal comfort and great heel hold. T-Drive Technology, a carbon spine that improves the boots consistency and efficiency100mm last TECNICA Mach1 MV 110 TD Ski Boot