Sea To Summit Ascent -1°C is a sleeping bag designed to be one of the most multi-purpose of the entire line, so you can use it for long-distance hikes as well as weekend getaways. Filled with RDS goose down with the waterproof Ultra-Dry Down treatment and a filling power of 750+, which means that one ounce (30g) of down will expand over 750 cubic inches after compression. Higher fill power means that less down can be used to achieve the same temperature, which is important for high-performance sleeping bags. Its shape is mummy-shaped but with a generous size to increase comfort inside. In addition, the QuiltLock system includes button clips on the shoulders and feet so that a duvet is incorporated and you can sit, comfortable and warm even when you are not sleeping. Other details, like the entire Sea To Summit line, are thought out to the smallest detail: main zip with opening down to the feet to regulate internal temperature and 1/2-length secondary zip, large padded hood to keep the heat in, which can be paired with all Sea To Summit women's models. Sea to Summit Ascent -1°C sleeping bag