When we're after lightweight warmth and packability, we select the Norrona Trollveggen Superlight Down850 Vest out of our gear closet. It features 850-fill power down for optimal loft and packability, keeping us warm with little weight and limited bulk. The slim cut has a flattering fit when we wear it as an outer layer, and it slips easily under a shell for a lightweight mid-layer to maintain our core temperature on cold-weather hikes, ski tours, and mountaineering missions.