If you're looking for a high-quality and really lightweight sleeping bag with a small pack size for your next big trekking trip, you ought to have a look at the Koteka II 290 down sleeping bag from Sir Joseph. This sleeping bag weighs in at only 520g and has a comfort temperature just above freezing.For insulation, Sir Joseph opted for European goose down with a fill power of 850 cuin. Constructed using Pertex Quantum Y, the sleeping bag offers excellent insulation, comfort, breathability, water repellency and excellent wind repellency. Plus, despite how light the material is, Pertex Quantum has strong tear strength as well. The chambers serve to distribute the down evenly throughout the bag and keep it from shifting. The side zip makes it easy to slip in and out of, just in case nature calls. When packed in the compression sack, the sleeping bag has such a small pack size that you'll hardly notice it!If you like trekking in low mountain ranges, in northern regions or in between seasons, the super-light and durable Koteka II 290 down sleeping bag is an excellent choice.