When you need an ultralight, compressible backcountry layer that is seriously warm, look no further than the Trevail Jacket. Loaded with 800 fill goose down, it traps body heat to keep your temperature consistent no matter how cold it gets on the trail. Internal elastic cuffs and a hem cinch cord help lock in extra warmth when navigating challenging terrain. When things heat up, you can unzip the front and let in some cooling airflow, or take it off and stow it in its own pocket. An internal chest pocket lets you stash small essentials.