Lightweight and packable, the Sitka Gear Kelvin Jacket has an extreme heat-to-weight ratio. Using synthetic high-loft insulation called PrimaLoft Sport, this hunting jacket is designed to distance the atmospheric climate from your skin. Built for the most extreme and cold situations, this camo jacket is serious business. Designed to layer underneath an appropriate outer shell, the Kelvin hunting coat is Sitka"s warmest insulating jacket. 170 g/m2PrimalLoft Sport Insulation Sitka Gear Optifade Kelvin Jacket Features: Packable insulation Two chest pockets Articulated arms Internal waist cinch Extreme heat-to-weight ratio Fabric Details: PrimaLoft Sport Insulation (170g/m2), 100% Polyester PrimaLoft Technology PrimaLoft is the ultimate in insulation technology for hunters. The patented blend of microfibers is engineered to retain maximum warmth even when wet. Ultra-fine insulating fibers create a product that is quiet and less bulky, allowing for greater freedom of movement. Easy care PrimaLoft provides the warmth of down, but it is fast drying and more breathable.