Utilizing technologies derived from alpine touring ski boots, the Salewa Men's Vertical Pro GTX Mountaineering Boots feature a walkclimb mode, which makes the boot comfortable during the approach and fully rigid when climbing. The system is composed of an aluminum stay embedded into the last of the boot. When in walk mode, the stay loosens, giving the boot enough flex for you to walk comfortably. Once locked into climb mode, the aluminum stay becomes completely rigid, giving the boots the stiff and supportive feel needed when climbing snow and ice. The upper of the boot is composed of Perwanger suede along with a protective full wrap rand to resist abrasion from rock and ice. Backed by a Gore Tex membrane, the boot is waterproof and lightly insulated with Thinsulate. The 3F ankle support system is designed to secure your foot in the heel pocket without restricting ankle mobility while you walk. This makes the boot more comfortable to hike in than traditional mountaineering boots. The alpine specific Vibram Salewa Pro sole is step in crampon compatible.