What Our Gearhead(R) Experts Are Saying:"This jacket is my go-to when I need packable insulation that still punches above its weight. It's light, windproof, and warm-even when wet. I've used it for alpine approaches, ski tours, and early-season camping. It layers perfectly under a shell and disappears in my pack when I'm on the move."When cold air cuts across a ridgeline or settles in after sunset, we reach for the Norrona Falketind Thermo40 Hooded Jacket. Designed for four-season mountaineering but built versatile enough for everything from brisk treks to ski tours, this synthetic jacket balances warmth, breathability, and weather protection in a featherlight package. The aeroDownproof outer fabric blocks wind while maintaining a soft, lightweight feel. Inside, 40g of recycled thermo40 insulation traps warmth efficiently-even when damp-and compresses easily into a pack. The technical fit features articulated arms and an extended back for better coverage under a harness or pack, while the helmet-compatible hood, chest pocket, and elastic cuffs deliver dialed-in function for high-alpine movement. It's our lightest synthetic insulator, built for everything cold and fast.