Think of the liner in the Mach1 105 W as a well-designed Italian shoe and you’ll get the gist of Tecnica’s C.A.S. technology, which combines a lower scalloped cuff and sculpted lower shell with a narrow heel pocket, contoured areas that honor the foot’s shape, and an asymmetrical toe box. The liner also features Quadra Fit or a combo of four different materials and densities designed for better fit and warmth. An advanced through expert all-mountain boot, the Mach1 105 W has a medium-fitting 100 mm last, 105 flex and Technigrip soles or sold separately, pre-canted soles for tricky alignment issues.