The Hydrogen is a remarkably lightweight and compact sleeping bag from Marmot, offering excellent insulation for three-season hikes or treks. With a Pertex® outer shell, 800-fill power goose down insulation, and a water-resistant Down Defender treatment, the Hydrogen keeps you warm and dry throughout your night in the wilderness. After a long day of hiking in the mountains, you can rest your feet in the spacious and enveloping foot box of the Hydrogen. The multi-baffle Nautilus hood with drawcord, snag-free insulated draft tube, and two-way zipper with anti-snag slider of the Hydrogen minimize heat loss. Lastly, the Hydrogen features an internal stash pocket where you can safely store your small valuables. Shape: Mummy Seasons: 3 seasons Outer material: 100% recycled nylon Ultra-lightweight and compressible goose down with a certified 800+ fill power and an eco-friendly ExpeDRY water-repellent finish that enhances performance and durability with reduced drying time. The anti-snag slider on the main zipper and the second fold-down zipper provide extra ventilation and make it easy to get in and out of the sleeping bag. Anatomically designed foot box with wrap-around construction increases warmth. Curved and smooth baffles prevent down from shifting, enhancing the bag's durability and ensuring even warmth inside. ISO tested for temperature reliability and comfort scale. Fixed hood offers full coverage. Comfort temperature: 2°C Limit temperature: -3°C Extreme temperature: -19°C Continuous YKK zipper with dual sliders. 2 loops to hang the sleeping bag. Foot box designed for added warmth. Anti-cold hood with convenient drawcord. Multi-compartment Nautilus hood. Stash pocket for valuables. Compression and storage sacks included. Shoulder girth: 155 cm Hip girth: 142 cm Packed dimensions: 31 x 15 cm Marmot Helium - Regular: Recommended max height: 183 cm Bag volume: 4.6 L Fill weight: 320 g Sleeping bag weight: 665 g Marmot Hydrogen - Sleeping bag | Hardloop