These Extreme 3D bags have a breathable, water-resistant super-soft outer shell and a unique 3D side wall design for easy turning inside the bag with clothes on. Both the 3-5 season and the 4-season have an extra thick multi-layer hollow fibre filling for all year round use along with an integrated reversible pillow and fixation hoods at the top, bottom and a main fixation strap. 4 season rating Breathable and water resistant outer shell Heavy duty crash zips Unique 3D side wall design for easy turning inside the bag with clothes on Extra thick multi-layer hollow fibre for all year round use Fixation hoods on top & bottom for fixation Big main fixation strap Integrated reversible pillow