Terramar Men's Ec 2 Thermasilk Pant has 100% silk interlock knit construction produces a heavier weight fabric than the conventional filament jersey fabric. The heavier weight fabric of the Terramar Men's Ec 2 Thermasilk Pant retains all the luxurious soft, moisture thermoregulation characteristics of EC2¨ Qwik Dri, while adding extra warmth for winter's coldest days providing superior comfort in a layering system. So on winter's coldest days wear Terramar Men's Ec 2 Thermasilk Pants.