Cumulus X-lite 300

Cumulus X-Lite 300

Cumulus X-Lite 300 is an extremely light three-season down sleeping bag built for adventurers who count every gram. As part of the X-Lite series – the lightest sleeping bags in the world as far as the weight-to-warmth ratio is concerned – it is the perfect companion for trail running, ultramarathons, bikepacking, and sport rock climbing from early spring to late autumn.

The X-Lite 300 weighs only 465 grams, yet packs a full 300 grams of high-quality 900 Fill Power ethically sourced Polish goose down. With a comfort rating of 2 °C and a limit of -4 °C, it extends the X-Lite concept well beyond summer: where the X-Lite 200 covers warm spring and summer nights, the 300 handles chilly shoulder-season conditions, higher mountain camps, and cold clear nights – all at a weight most summer bags struggle to match.

This remarkable weight is achieved through the use of Toray® Airtastic 19 g/m² – the world’s lightest down-proof fabric. The bluesign® certified 7-denier ripstop nylon shell with DWR finish keeps moisture at bay while remaining highly breathable and incredibly light.

The sleeping bag features a trapezoid chamber construction with separately filled front and bottom, which maximizes down loft and eliminates cold spots – a more advanced chamber design suited to the higher fill weight of this model. The close-fit mummy shape further improves thermal efficiency, delivering dependable insulation with an absolute minimum of material.

Unlike its hoodless smaller sibling, the X-Lite 300 features a 3D-shaped hood that wraps efficiently around your head to seal in warmth on colder nights. Two separate draw cords allow comfortable, intuitive adjustment even in complete darkness, without reaching for your headlamp.

Guided by a strictly minimalist design philosophy, the X-Lite 300 is free from unnecessary components that would increase its weight. Despite this, comfort has not been compromised. The anatomical shark-fin foot box supports the natural position of your feet, eliminates empty air spaces, and delivers maximum warmth in one of the most cold-sensitive zones of the bag.

The 2/3-length 3 mm YKK® zipper with two self-locking sliders allows the bag to be opened from the top or ventilated during warmer nights, while the partial length keeps the calf and foot area fully insulated. A down-filled insulating tube running along the zipper prevents heat loss in this area. For even colder conditions, the X-Lite 300 can be combined with other X-Lite series bags to extend its temperature range.
Practical details complete the package: a lightweight stuffsack compresses the bag down to a compact 3.5-liter package, while the included storage sack keeps the down lofted between adventures.

For hikers, runners, and bikepackers who accept no compromises when it comes to pack weight, the Cumulus X-Lite 300 offers an unmatched combination of premium materials and radical minimalism. It is the ultimate choice for fast-and-light three-season adventures – from frosty spring mornings to cold autumn nights – where every gram and every cubic centimeter counts.

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)
• Fabric certificates: bluesign®
• Construction: Trapezoid chamber design
• Separately filled front and bottom
• Close fit mummy shape
• 2/3 length, 3 mm YKK® zip with 2 self-locking sliders
• Down-filled zip insulating tube
• 3D shaped hood design
• 2 different hood draw cords for comfortable adjustment in the dark
• Minimalist, weight saving design and components
• Anatomical, shark fin foot box design
• Can be combined with other X-Lite series bags
• Stuffsack and storage sack included

MEASUREMENTS

Maximum user height: 185 cm
Length: 202 cm
Width (top/bottom): 77/42 cm
Weight of unfilled sleeping bag: 165 g
Stuffsack’s dimensions (height/diameter): 20/15 cm
Stuffsack’s volume: 3.5 l
Number of down chambers: 33