A sleeping bag liner provides extra protection against wind, moisture, dirt and also acts as an insulation. It is usually very light and takes up little space, so you can hide it in your rucksack and it will not burden your equipment. MILITARY.PL offers inserts for sleeping bags, which are usually made of quick-drying materials, so that after washing they are very quickly ready for the next use. They are manufactured from durable and pleasant to the touch materials.