Product descriptionRossignol say - Explore the back bowls and beyond the gates. The Alltrack 90 HV is a no-compromise boot that's designed to ski the whole mountain. A releasable cuff offers a natural range of motion for hiking and a 102mm last for a comfortable fit. The Generative Design Grid shell is engineered for reduced weight and full power transmission on-piste or off and everywhere in between. The custom liner offers enhanced comfort.GENERATIVE DESIGN GRID - A progressive new data-driven design approach that harnesses the power of generative design software to create the ideal boot shape. Focused on minimizing shell wall thickness for reduced weight while simultaneously enhancing power and support, our new GENERATIVE DESIGN GRID shell offers the most effective blend of both.DUAL CORE TECHNOLOGY - Our new "power injection" method allows the simultaneous injection of two different durometers of plastic at the exact same time. This unique mono-injection process allows targeted power transmission and shell wrapping; and creates our DUAL CORE sandwich construction throughout the shell, resulting in livelier rebound, response, and total control through the turn.HIKE MODE 2.0 - The new OPTIMIZED HIKE MODE includes a wider opening in the back of the lower shell, and a lower axis-of-rotation for optimized range-of-motion and uphill mobility (50⁰ ROM). The articulating lower shell insert and metal-on-metal locking mechanism increase rearward support while supplying maximum power transmission on descents.CUSTOM T4 - CUSTOM liners offer customization in the internal padding for enhanced foot wrapping and comfort. T4 version features mono-injected Polyethelene padding for a consistent soft density throughout performance and fit zones. Rossignol Alltrack 90 HV Ski Boot