Feathered Friends Eider EX -10 Sleeping Bag

The Eider EX -10 is Feathered Friends' expedition bag for winter mountaineering and snow bivouacs, rated by the manufacturer to -23°C (-10°F) and classified for five-season/expedition use. It's filled with 908 g of 900+ fill-power, RDS-certified goose down, bringing total weight to 1553 g. The Pertex Shield EX shell combines 15D and 40D ripstop with a waterproof/breathable membrane — unlike the DWR-treated shells on Feathered Friends' lighter bags, the Eider EX can take direct contact with snow or tent condensation without wetting out the insulation. A recycled 20D nylon liner, adjustable fitted hood, draft collar, zipper draft tube, and an internal pocket for small items like headlamp batteries round out the feature set; the fabric is bluesign-certified. At over 1.5 kg, this isn't an ultralight bag in the usual sense, but for an expedition-class model with a membrane shell rated to -23°C, the warmth-to-weight balance is solid. It's built for mountaineers, winter bivouacs, and expeditions rather than summer thru-hiking.