The Feathered Friends Winter Wren YF is a wearable sleeping bag rated to -3.9°C (25°F), designed with zippered arm holes so it can be worn like a parka around camp instead of sitting still inside it. A two-way center zip lets you vent from the top or bottom independently, and a drawcord footbox opening means you can free your feet and walk around in it — useful at a cold camp kitchen or during an early alpine start when you want warmth without fully packing the bag away.
It's filled with 900 fill power goose down and weighs 936 g total, with a 9 L packed volume and a trapezoidal footbox shape. Rated 3-4 season, it sits well short of the -10°F and 0°F expedition bags in the Feathered Friends range, making it a shoulder-season or cool-summer bag rather than a winter one. The wearable design is a genuine trade-off: it adds features a standard mummy bag doesn't have, aimed at hikers who spend a lot of waking time in camp at temperatures near freezing rather than sleeping through deep cold.