Comfort: -2°C (28°F) Limit: -8°C (18°F) Extreme: -27°C (-17°F) The premium sustainable choice from Rab and warmest in the range, made with 100% recycled materials and concertina style construction, trapping air to boost loft and warmth. Ideal for backpacking and mountain trekking, especially in cold, changeable weather. These resilient synthetic bags are filled with 100% recycled Stratusinsulation, and lined and covered with a tough, 20D, recycled Atmosfabric with ripstop. Hardwearing, warm, and dependable, they are fast drying and cope with condensation or damp conditions, ideal for the exposed bivi ledge or taking refuge in a snow hole. The Solar Eco 4 is insulated with a double layer of Stratusinsulation arranged in a concertina structure to trap warm air. The elastic internal quilting brings the lining and insulation closer to the user, helping to reduce pockets of cold air. The localised quilting simply means that the stitching which holds the insulation in place has been mi