Cold weather alpinism is the bane of most people’s toes, but extra warmth can often mean sacrificing performance. The Everest has no such problem, because it’s a fully integrated system of super gaiter, plastic shell, and removable inner boot. The Everest has a total of 15mm of Alveolite insulation, plenty to keep your feet warm to -50 ° F,. yet it’s easily compact - and lightweight - enough for excellent performance. The upper gaiter is Gore-Tex for waterproof, breathable comfort, and has a very handy two-zip panel for access to the shell/inner boot.