Designed for edge control and confidence in tough terrain, the Salomon S/Pro Alpha 120 GW Boot helps us drive our skis when we need precision. The 120 flex drives power to our edges, while the 98mm last, which can be expanded if needed, locks in a precise fit for narrower feet. The My Custom Fit 4D Race liners further lock our feet in place, so the power spine can do its work in helping us drive our skis.