Like Crocs with even thicker skin, the Expedition Crocodiles are our burliest gaiters and are designed to function on extended mountaineering trips, in cold weather and in extreme conditions. The large circumference provides more room for plastic mountaineering boots and heavily insulated pants, the upper leg is constructed of waterproof, breathable GORE-TEX, and the inside leg of each gaiter is made of durable Cordura® fabric to prevent crampon snagging and puncturing when you're high in the mountains.