The Arc'teryx Men's Cerium SV Hooded Down Jacket is built with extreme functionality in mind, specifically for those challenging backcountry and alpine situations. When your life depends on your gear, the last thing you want to be thinking about is whether or not your jacket is up to the task. The Cerium starts with down composite mapping, which strategically places down and synthetic insulation into key areas. A DWR coating is used on the lightweight Airetica face fabric to help repel minimal amounts of moisture. Let's face it though, the places you're likely using this jacket, it's so high and cold that there's not much moisture around anyway. A stuff sack is included with the Cerium as well so it's not crowding up your pack.