Say hello to your new go-to piece for all your mountain activities, the Arc'teryx Thorium AR Hooded Down Jacket. This generalist down jacket functions well as a standalone option when hiking in cool, dry conditions, and it's also an excellent choice for layering under a shell when you need extra warmth during frigid backcountry ski tours or alpine ascents. Its 750-fill down insulation is lightweight, yet very warm, and it's highly compressible for comfortable layering and easy storage when you don't need it. Synthetic insulation is strategically placed in areas that are more exposed to the elements, so that you still stay warm even if the insulation in those areas gets a little damp. The outer fabric also sports a DWR coating to repel light rain and snow, just in case you get caught out in a drizzle without an outer shell, and it's highly abrasion-resistant for peace of mind. Low-profile, elasticized cuffs and an adjustable drawcord hem seal out the cold, and an internal zippered pocket doubles as a stuff sack so you can efficiently stow the jacket in your pack if it starts to warm up halfway through your adventure.