Helium Down Jacket

For cold and dry, down is still king, and the Helium Down is Outdoor Research ultralight take on it: 800-fill down under a whisper-thin Pertex shell, packable to nothing and warm for its weight in a way synthetic cannot match in dry cold. Know the flip side of that coin - down loses loft when it gets wet, so this is a jacket for crisp alpine mornings and dry winter cold, not for damp, drizzly days where a synthetic like the SuperStrand pulls ahead. The thin shell also wants care around abrasion. For gram-counting alpinists and anyone layering for reliably dry cold, it is a superb warmth-to-weight buy.