The Mach1 series target high-performance skiers looking for a precise anatomical fit. The Mach1 120 MV has a 100mm last, fitting most average feet, with a nice and tall instep and new wider toe box. For a life-long skier, that is used to 'how boots fit', this boot fits a fairly high-volume foot. The 120 flex is powerful and supportive for high performance carving or crud busting, but not so stiff that it locks the ankle. The new T-Drive technology creates a stronger and more effective connection between the shell and the cuff, on the 120 MV the T-Drive spine is made from fiberglass. The longer lever arm prevents deformation as the boot flexes, giving a smooth and progressive feel. Less shell deformation means more precision and more efficient energy transmission to the ski. Heavier advanced skiers and average sized expert skiers will love the performance offered by the Mach1 120 MV. The C.A.S. shell has many of the common 'fit issue points' of the boot pre-shaped for out-of-the-box comfort, additional stretching or grinding is simple on this full polyether shell. The medial wall of the shell has thicker plastic and the lateral wall has thinner plastic, this keeps weight down and precision up. The C.A.S. liner is heat moldable and easy to modify. Celliant insulation provides warmth. The floating tongue can be raised and lowered; this can really impact comfort for the shin.