Aptly named for its ability to withstand severe weather conditions i. e., SV, the Arc'teryx Thorium SV Men's Down Jacket is a wondrously warm standalone piece for cold, dry conditions, also performing admirably under a waterproofbreathable shell when outside wind and moisture threaten your alpine climb, ski mountaineering adventure, or cross town jaunt. Using Arc'teryx's Down Composite Mapping technology, the lofty 750 fill European grey goose down throughout the body provides fiery warmth in cold to frigid conditions. Realizing that down's heat trapping loft becomes compromised once wet, Arc'teryx placed Coreloft 100 and 140 synthetic insulation throughout areas prone to moisture build up from outside elements and perspiration, such as the hood, cuffs, and underarms. The result is a down synthetic hybrid jacket that retains warmth during aerobic alpine activities, such as ski mountaineering, alpine climbing, and cold weather trekking. For the jacket's shellouter fabric, Arc'teryx placed Arato40 nylon, which is a lightweight, yet extremely durable material that stands up to regular use and abuse in the alpine. This shell is finished with a DWR to bead off outside moisture from seeping through and compromising the down insulation inside. Further contributing to the jacket's high levels of warmth, Box wall baffles maximize loft, enhancing the down's ability to retain body heat in cold conditions. Other key features include a low profile, helmet compatible StormHood, elastic bound cuffs, drawcord adjustable hem, interior stash pockets, and No Slip Zip front closure.