Streamlined ThermoBall ® powered by PrimaLoft ® baffles are contoured to fit your body and maintain core warmth during winter excursions in cold, wet weather. 15D 33 g/m2 100% nylon with DWR finish 11.5 g/ft2 PrimaLoft ® T The North Face ThermoBall Trekker Vest. NF0A3LHD