It's winter, and you are above the tree line with everything you need to survive stashed in your backpack. And you're wearing your Jack Wolfskin Aquila Jacket . The shoulders and chest are reinforced with lightweight STORMLOCK fabric. This fabric is water resistant and protects you from the cold wind.The AQUILA can be worn as a warm layer under your hardshell when you're trekking and is equally reliable as an everyday jacket. The jacket has an athletic cut and is made of warm NANUK fleece with a special marled appearance. Fleece has never looked as natural as this.