These U.S. Military Mickey Cold Weather Boots, aka Vapor Barrier Boots, use a rugged arctic-tested design used by generations of explorers, not to mention cold weather warriors. Insulation comes from a layer of "dead air" which prevents convective heat loss and minimizes conductive heat loss. These Boots continue to prevent hypothermia and frostbite in temperatures down to -30AdegF. Foot temperatures are unaffected by moisture, and the boots retain their insulating power even if socks become totally saturated (like from sweat, condensation, or snow melt). The built-in air valves are designed to protect the dead air pockets from becoming ruptured during high-altitude flight or other large pressure changes. Double-thick rubber Dead air pockets plus wool felt insulation Comfort rated down to -30AdegF Nylon lined interior High-traction soles and heels Heel wedge accepts ski or snowshoe bindings Air valve for high-altitude transport Each approx. 11.5"h. Each approx. 53 oz.