Fellkit

Rab

Rab Neutrino Down Sleeping Bag (-12°C), 2026 model

Best use

Made for
Winter mountain
Also works for
Backpacking and wild camping
Why these labels
  • Winter mountain: The maker states this use, and the published specs do not rule it out.
  • Backpacking and wild camping: Light to carry: 1.1 kg

From the maker's stated use and the published specs.

  • Summer wild camp: 5/10 UK, roughly May to September, nights above about 8 °C, sheltered pitches.
  • Three-season hills: 7/10 UK hills in spring and autumn. Wind, rain, and nights near freezing.
  • Winter camp: 8/10 UK winter or high ground. Below freezing, strong wind, possibly snow.
  • Weight: 6/10 How much it adds to your pack, compared with the whole market.

Comfort -5 °C, limit -12 °C (ISO 23537).

Lowest price we found

£484.99 at Ultralight Outdoor Gear

In stock. Free delivery. Checked 8 Nov 2026.

RRP £570, checked 19 Oct 2026.

Go to Ultralight Outdoor Gear Compare 2 shops

UK winter camping and three-season hills where nights fall to about -5 °C

Comfort
-5 °C
Limit
-12 °C
Fill
800 fill down
Weight
1.07 kg (Regular)
Packed size 11 L, 35 cm long and 20 cm across Compare with a 2-litre bottle

A bit longer than a 2-litre bottle and about twice as wide. Drawn to scale.

Where to buy

Ultralight Outdoor Gear £484.99 In stock. Free delivery.

View at shop: Ultralight Outdoor Gear

Sports Shoes £512.99 In stock. Free delivery. Free express 24-hour delivery on this item.

View at shop: Sports Shoes

Alpinetrek £512.96 Out of stock. Regular out of stock; only the Long is in stock.

View at shop: Alpinetrek

Rab £570 Out of stock.

View at shop: Rab

Prices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More

Our ratings (out of 10)

1 to 10, compared with the whole market. Each says what it's based on. How we score

Warmth

From maker's figures 9/10

How cold a night you can sleep comfortably through. 9: Among the best you can buy for this.

Rab's ISO 23537 comfort -5 °C (limit -12 °C, extreme -33 °C) sits in the -5 °C or colder band. The maker's figure, not re-tested.

Room inside

Estimate from maker's specs: maker's shoulder girth (fewer than 3 reviews about room) 6/10

How much room to move, bend your knees and sleep on your side. Roomier is comfier. 6: A bit better than average.

No review we found says how roomy it is, so this is an estimate from the maker's shoulder girth.

Weight

From maker's figures 6/10

How much it adds to your pack. 6: A bit better than average.

Rab lists 1,070 g for the Regular, in the 1,000-1,299 g band. Ultralight Outdoor Gear lists 1,119 g, which is the same band.

Packed size

From maker's figures 3/10

How much room it takes in your rucksack. 3: Below average. Fine for some trips, not others.

Rab gives only two figures, 20 cm x 35 cm, so it is a stuff sack: 3.1416 x 10 x 10 x 35 = 10,996 cm3, 11.0 L, in the 9-12.9 L band.

In short

Good for

  • UK winter camping and three-season hills where nights fall to about -5 °C
  • Cold sleepers who still want the bag near 1.1 kg and packing to about 11 L

Strengths

  • ISO 23537 comfort -5 °C, limit -12 °C, in a 1,070 g bag
  • 600 g of 800 fill power goose down with a fluorocarbon-free hydrophobic finish
  • L.O.F.T 3D baffles and sidewall baffles to cut cold spots; the 3/4-length zip has a down-filled baffle
  • Sold in Regular, Wide and Long, and as a Women's version

Weaknesses

  • A tapered cut: side sleepers and restless sleepers may want the Wide size
  • Down loses warmth if it stays soaked, so a long wet trip favours a synthetic bag
  • No independent review of this exact bag yet, so Damp, Comfort and Durability are estimates, not reviewed scores

Sources

We haven't tested this ourselves. Every score comes from these specs, tests and reviews.

ShowHide sources (1)
  1. Rab: Neutrino Down Sleeping Bag (-12°C) product page (ISO 23537 rating, weight, packed size) Specs, 19 Oct 2026. Used for: warmth, weight, packed size