Rab Neutrino -18°C Sleeping Bag | Down Bag for Winter Mountaineering

Description

The Rab Neutrino -18°C is a down sleeping bag designed to offer maximum thermal protection with a still-contained weight for winter alpine activities, technical bivouacs, and cold mountain environments where insulation leaves no room for compromise.

With 800FP European goose down, L.O.F.T 3D™ construction, and a strategic distribution of Pertex® Quantum fabrics, this model is positioned in the warmest zone of the Neutrino family, designed for winter ascents, high-altitude mountaineering, and outings where sustained cold demands a serious, packable, and technically capable bag.

Real technical performance

Within the Neutrino range, this model is clearly oriented toward real winter use. It maintains the family philosophy—excellent warmth-to-weight ratio, compressibility, and an alpine focus—but raises the level of insulation for cold nights, altitude, and demanding bivouacs.

The L.O.F.T 3D™ construction reduces down migration and improves thermal uniformity, while the use of 20D Pertex® Quantum on the base and footbox provides greater durability in areas of wear and compression, leaving the 10D Pertex® Quantum on the top section to maintain lightness and packability.

The mummy taper fit, thermal collar, anatomical hood, and zipper baffle help minimize heat loss when conditions truly get tough.

Quantitative technical specifications

• Weight: 1280 g
• Fill: 800FP European goose down with fluorocarbon-free hydrophobic finish
• Fill weight: 800 g
• Main outer fabric: 10D Pertex® Quantum ripstop (26 g/m²) with fluorocarbon-free DWR
• Secondary outer fabric: 20D Pertex® Quantum ripstop (38 g/m²) with fluorocarbon-free DWR
• Lining: 20D recycled nylon, 38 g/m²
• Comfort temperature: -10°C
• Limit temperature: -18°C
• Extreme temperature: -40°C
• Packed size: 22 x 40 cm
• Construction: L.O.F.T 3D™
• Shape: Mummy taper fit

Comparison within the range

The Neutrino 0°C and Neutrino -6°C cover alpine shoulder seasons and cool mountain conditions. The Neutrino -12°C enters a colder and more versatile winter territory. This Neutrino -18°C represents the warmest step in the standard family, designed for serious winter conditions, technical bivouacs, and users who need more thermal margin without jumping to expedition ranges.

Compared to heavier or less technical ranges, it offers a very solid proposal for winter mountaineering with a better balance between weight, volume, and thermal performance. Compared to the Mythic range, it prioritizes a robust construction and broader use in real cold.

Recommended use

• Winter mountaineering
• Technical bivouac in high mountains
• Ascents in sustained cold
• Alpine trekking and lightweight expeditions in very cold conditions

Is it for you?

Yes, if you are looking for a technical down sleeping bag for real winter, with high insulation and a highly competitive warmth-to-weight ratio.

Yes, if you bivouac, engage in mountaineering, or visit cold mountain environments and need a bag that is clearly warmer than a 3-4 season model.

No, if your primary use will be summer, mild trekking, or mountain huts. In that case, the lighter Neutrino models or less thermal ranges are a better fit.