Streamlined ThermoBall® powered by PrimaLoft® baffles are contoured to fit your body and maintain core warmth during winter excursions in cold, wet weather. Wear this thermal vest as a mid-layer for added warmth in the coldest winter days or pack it for emergency layering in the backcountry. 15D 33 g/m2 100% nylon with The North Face - Men's ThermoBall™ Trekker Vest