Product Information for Rocky Product Description This military boot has a water resistant leather and Cordura® nylon upper with a PTFE flame resistant coating and a waterproof and breathable GORE-TEX® membrane, 400 grams of Thinsulate™ Ultra insulation, a moisture wicking Dri-Lex lining with an Aegis® anti microbial shield, a Lycra® tongue, SuperFabric™ instep panels, drainage grommets, a fiberglass shank, a Rocky® AirPort™ footbed, and a high walled Vibram® outsole. Additional Info GTX , GORE-TEX® , Thinsulate Fit: True to Size