Wellco N-1B Air Force Snow/Extreme Cold Weather Mukluks Boots, Made in USA Worn by USAF in Extreme Cold and Snow (Made in USA!) Water Repellent & Fire Resistant; Lace & Zip Up 100% Cotton Duck Uppers & 100% Rubber Soles MUST BE WORN WITH ONE OR TWO PAIR OF THICK WOOL SOCKS MENS SIZING GUIDE (U.S. Sizing): Small fits 7-8, Medium fits 9-10, Large fits 11-12, X-Large fits 13-14