Description Nubuck Leather & 1000 Denier Nylon Upper: For abrasion- and scuff-resistance, we use full grain nubuck leather combined with lightweight, breathable Denier nylon. This combination offers some of the best protection in cold and wet environments. Mesh Lining: Lightweight and breathable for total foot comfort. USMC Certified: Developed for the United States Marine Corps, this boot has served expeditions around the world. Speed Lace System: Our special hardware allows you to tighten from toe to top with one swift tug for a secure, tight fit. Vibram® 360 Dri Ice Outsole: An advanced lug design combined with Vibram’s Dri-Ice compound keeps this outsole flexible and stable in extreme cold. Extended Sizes: To accommodate more people, we’ve made this boot in extended sizes. We recommend women select 1.5 to 2 full sizes down for correct fit. Stitchdown Construction: Handcrafted to provide a wider platform, our legendary stitchdown construction offers increased stability underfoot. Many of our stitchdown boots can be recrafted. How It Fits: The 610 is our most universal last and can be worn by all foot shapes and sizes. It provides a snug fit through the heel while allowing ample toe room for most versatile fit. This allows more support and side-to-side movement. Recraftable: Extend the life of your boot with our recrafting services. This boot is eligible for a number of paid services, including part replacement, leather care and restitching. See our Recrafting page. 365-Day Warranty: If you suspect your purchase isn’t up to our unrelenting standards, or is defective in any way, we want to make things right. We offer a 365-day warranty across our entire footwear and apparel lines.