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 Durable Water-Repellent (DWR) Finish. 11.5 g/ft2 PrimaLoft ThermoBall Synthetic Insulation. Secure-Zip Hand Pockets . Stows In Left Hand Pocket. Hem Cinch-Cord. Complies with Prop 65.