The warm three-season sleeping bag Mons 500 is made of light nylon fabric with a filling of seven-chamber hollow fiber, which has excellent filling and insulating properties. The fabric is made of very light micro nylon 380T with DWR (Durable Water Repellent) treatment, which makes the fabric breathable and water-repellent at the same time. The sleeping bag is very light and thanks to the compression package, it can be packed into a small package, so it does not take up much space in the backpack. Thermal properties were tested according to EN ISO 23537-1:2016. Hollow fiber has very good insulating ability and low weight, does not absorb moisture and dries very well. Nylon is pleasant to the touch, resistant to damage and permeable to evaporated moisture. Thanks to the DWR treatment, it provides partial protection against water, mainly against drops of condensed water in the tent, and thanks to this, the sleeping bag dries quickly.