Compression sack allows you to reduce the volume of things several times, which significantly saves space in the backpack. The UL Compact model combines exceptional lightness and functionality.
The sack is made of ripstop nylon, which prevents tears. All materials have a moisture-repellent finish, so things inside will be protected from condensation and light rain.
Fastex on one of the straps allows you to quickly open or close the case without having to loosen all the straps (present in all sizes except XS).