We integrate stretch insulation in our Fusion collection, featuring 3M™ Thinsulate™ Stretch Insulation that moves with the outer fabric so your outerwear moves when you do. The elastometric insulation guarantees a layer of warmth that gives your outerwear the freedom to expand and contract along with the outer fabric. Years of research in the Aspen mountains have taught us that stretch is invaluable for proper fit and range of motion for sporting activities.