X-LITE 400

As low as €485.00

- +
3-6 working days

The X-Lite series are the lightest sleeping bags in the world as far as the weight-to-warmth ratio is concerned. Reducing the weight of equipment is our most important mission, carried out thanks to our long experience in redefining the word 'lightweight'. We have used a whole range of solutions to achieve this objective: this sleeping bag is made of the world's lightest down-proof fabric, 19-gram Toray Airtastic®, but we have also used a light, 3 mm 2/3 length zip and ensured a slim fit, which at the same time allowed us to improve the insulation. In designing, our focus was on minimalism and, for this reason, X-Lite is free from unnecessary components which could increase its weight. Still, it can be used comfortably, owing to such features as the anatomical foot box (shark fin) and the 3D hood structure. Such a remarkable product required an equally unique fill: ethically sourced, 900 FP Polish goose down. X-Lite is perfect when quick pace matters, regardless of whether you want to do trail running, ultramarathons, bikepacking or sport rock climbing. If you want your equipment to be compact and save weight, X-Lite is the best choice for you.

More Information
Down quality900 FP
Total weight575 g
Down weight400 g
Weight of unfilled sleeping bag175 g
Comfort temperature-1 ℃
Limit temperature-7 ℃
Extreme temperature-24 ℃
Maximum user height185 cm
Length202 cm
Width (top/bottom)77/42 cm
Stuffsack’s dimensions (height/diameter)25/16 cm
Stuffsack’s volume5 l
Number of down chambers33
Product features
  • Fill: 900 Fill Power ethically sourced Polish goose down
  • Shell and liner: Toray® Airtastic 19 g/m², 7-denier ripstop, DWR finish (100% nylon)
  • 2/3 length, 3 mm YKK® zip with 2 self-locking sliders
  • Minimalist, weight saving design and components
  • Down-filled zip insulating tube
  • Close fit mummy shape
  • Anatomical, shark fin foot box design
  • 3D shaped hood design
  • 2 different hood draw cords for comfortable adjustment in the dark
  • Construction: Trapezoid chamber design
  • Separately filled front and bottom
  • Can be combined with other X-Lite series bags
  • Stuffsack and storage sack included

Expert quality


Years of breeding experience, a specific climate and research facilities are the secrets behind the excellent parameters of Polish down, which is considered to be the best in the world. Despite technological advancement and attempts to make artificial insulation that would be just as reliable, down still remains unrivaled.

Ethical sourcing

We only use down from certified Polish producers. Thanks to their geographical proximity, we can monitor the production. We are absolutely sure down used by Cumulus has been ethically sourced. It is from free-range geese that have access to water. The excellent breeding conditions are also reflected in the down’s high quality.


Pertex® and Toray®, two fabrics we commonly use in our products, are made in Japan. Renowned in the outdoor world, they are both high-performers and have an impressive resilience considering their lightweight structure. At 19g/m2 Toray Airtastic® is the lightest downproof fabric in the world.


YKK® is the most trustworthy zip producer in the world, whose zips highly outperform the competition. Almost all our products feature YKK® zip - from clothing, accessories, to sleeping bags.