This superb value bag is filled with Iso Fibre, a highly siliconised synthetic filling that has a softer feel, lower water absorption & a longer lifespan than normal hollow fibre fillings. The outer of the bag is a tough rip stop Nylon & it is lined with Snugpaks own Supersoft fabric that wicks moisture, dries quickly & feels good next the skin. The tapered mummy shape helps to maximise the insulation & the whole thing packs down to 23 x 23 cm fully compressed, which is easily small enough to fit into most trekking packs. The comfort rating of this bag is 0 Celsius, this is based on the assumption that you will be wearing light clothing, & sleeping on a good quality insulating mat inside a tent. This is the only measure of warmth that we recommend you use. Compression stuff sack included for compact carrying Measures 23cm x 23cm when fully compressed Temperature rating: Comfort: 0°c, Extreme: -7°c Highly siliconised synthetic fibres give a soft touch finish & prolonged lifespan compared to traditional hollowfibre filled products. Mummy shape for retention of body heat.