The Trollveggen vest is the lightest made by the Norrøna, utilizing top-quality RDS-certified down. Some t-shirts weigh more than this vestthe Trollveggen is truly an impressive product. It's a great choice when you need a small dose of extra warmth without adding much weight or taking up much packing space. Depending on the situation, the vest can be worn as an outer layer or under a lightweight shell jacket. The down has a fill power of 800this number indicates the volume that one ounce of down can fill. Fluffy, top-quality down packs down very small and weighs little relative to its insulation capacity. - "Technical fit": the manufacturer's second-slimmest cut - Protective collar - Zippered hand pockets - Elastic binding at the hem and armholes - Longer hem at the back - Down is bluesign and RDS certified The vest's outer fabric features a water-repellent and quick-drying treatment, implemented without PFC compounds.