For the mountaineer looking for a compact, cold-weather bag léger, the Neutrino 400 offers exceptional compressibility and warmth for its weight. Constructed from lightweight, high-performance materials in a narrow sarcophagus shape, it reduces the bag's bulk, weight and size. Perfect for 3-season use in the mountains.

The Neutrino 400 Women's is filled with 400g of goose down with a loft of 800 cuin, stabilized in a herringbone divider cleverly designed to reduce the amount of fabric needed compared with traditional horizontal divider designs. The trapezoidal partitioning allows the down to inflate fully, eliminating cold spots and optimizing warmth. Additional flaps along the zipper and around the neck reduce heat loss, and thanks to the adjustable drawcord around the hood, you can tighten the bag around your face. The women's version is slightly shorter, narrower in the shoulders and wider in the hips than the classic cut bag, for improved efficiency.

Now made with a recycled nylon lining and a recycled Pertex® Quantum exterior, it's windproof and a little more léger for the planet too. The down is also treated with Nikwax, a hydrophobic fluorocarbon-free product designed to combat condensation. It features a ¾-length zipper with hook-and-loop protection, an inside zipped pocket and a waterproof bag for easy storage.

Hand-filled in the UK, tous our down sleeping bags benefit from never having been compressed before use, retaining their warmth and loft.

Weight:765g/27.0oz
Insulation:800 fill European goose down with fluorocarbon-free Nikwax hydrophobic finish (400g / 14.1oz)
EN (13537:2012) Temperature rating:ISO EN: Comfort: -1°C (30°F), Limit: -7°C (19°F), Extreme: -25°C (-13°F)
Sleep limit Rab:-7°C / 19°F
Packaged size:36cm x 19cm (14.2in x 7.5in)
Product code:QSM-91
Ripstop fabric in nylon Pertex® Quantum 20D (38 g/m2) with fluorocarbon-free DWR
Lining application: nylon 20D recycled fabric (38 g/m2)
800FP European goose down with fluorocarbon-free Nikwax hydrophobic finish (1000g / 35.3oz)
Trapezoidal boxwall construction reduces down migration and optimizes warmth in the trunk area.
Trapezoidal boxwall construction with differential cut, to maximise loft and warmth
Adjustable neck flap to reduce heat loss
3/4-length YKK main zipper with synthetic-lined flap to retain heat
YKK zipped internal stash pocket
Angled foot box for relaxed sleeping posture
YKK Anti-snag zip insert and anti snag internal zip guard
Hand-filled in Derbyshire UK
Zipped bag with waterproof base for storing your belongings at home
Waterproof compression bag with flap closure included
Main fabric: 100% recycled polyamide Lining application: 100% recycled polyamide
Tapered mummy shape