Updated for 2014 with streamlined PrimaLoft® ThermoBallTM baffles contoured to fit and flatter your body, maintain your core warmth while winter camping in cold, wet weather with our latest advancement in lightweight insulation technology. Our new synthetic insulation technology features round ThermoBallTM clusters that trap and retain heat to achieve phenomenal warmth in cold, wet weather. Wear this thermal vest as a mid-layer for added warmth on the coldest winter days, or pack it for emergency protection in the backcountry.