Ultra-compact down sleeping bag for summer bivouacking
The Aegismax Nano sleeping bag is designed for those who want to sleep outdoors in the summer without being weighed down. When the priority is to reduce the backpack weight to the bare essentials, this ultralight sleeping bag allows you to travel with only what you need, while maintaining a minimum of thermal comfort for mild nights.
A minimalist sleeping bag for lightweight sleeping in mild weather
The design clearly prioritizes weight savings with RDS-certified down. The fill is reinforced on the upper part of the body, where heat loss is most noticeable, while the rest of the bag uses a lighter construction. In practice, it functions as a 5-degree sleeping bag for dry summer nights, when used with a suitable insulating mat.
The outer fabric made of 20D ripstop nylon with a DWR treatment helps handle light moisture, morning dew, or condensation under a tarp. The 3D footbox provides better comfort for the feet, and the two-way YKK zipper allows the bag to be opened wide when temperatures rise. The Aegismax Nano is suitable for summer hiking, lightweight bivouacking, and travel where volume and weight take precedence over warmth, for those who want a compact sleeping bag that is simple and consistent with use in mild weather.
The redesigned version of the Nano — 800FP fill, box baffles, 5°C comfort range — is the Aegismax Nano 2, at 624 g for the Regular size.
Why pay more for the same performance?
The Aegismax Nano was compared with the Millet Light Down 11°. The finding is simple: you get equivalent technical features and warmth without paying the brand premium. Keep your budget for your next expedition.
Data checked against the brands' official product pages — subject to change.
Doubt about which bag is right for you?
The field guide helps you choose based on skill level, temperature, needs, and weight. Support answers specific questions.
Find my bag Contact supportFrequently Asked Questions
The Aegismax Nano has a comfort temperature of 10°C and a lower limit temperature of 5°C, measured to the EN 13537 standard. These values apply under standard conditions: sleeper in thermal base layers, on an insulated sleeping mat. It is designed for hiking, trekking use (3 seasons).
The Aegismax Nano is filled with Ultra-dry 700-fill-power white goose down, RDS certified. Down offers the best warmth-to-weight ratio: it packs down small and weighs less than synthetic insulation of equivalent warmth, which makes it the natural choice for wild camping and multi-day trekking. On the other hand, it loses efficiency when damp and needs careful drying. The Aegismax Nano weighs 544 g, which places it in the ultralight category.
A 3-season sleeping bag is designed for spring, summer and autumn. Its comfort temperature sits between 0°C and +5°C, which covers most wild camps in France up to 2,500 m outside winter conditions. In winter or above 2,500 m, a dedicated cold-weather bag is needed.
A 3-season bag is suited to night-time temperatures between roughly 0°C and +15°C. Below 0°C, thermal comfort is no longer assured without extra equipment (liner, additional sleepwear). Above +15°C, most sleepers will find the bag too warm: venting through the foot zip helps regulate.
For the vast majority of walkers and trekkers in France (GR20, GR5, Tour du Mont Blanc from June to September), a 3-season bag with a 0°C comfort rating is sufficient. A 4-season bag is only needed above 3,000 m outside summer, in winter conditions, or for exposed high-altitude wild camps in autumn.