Rab
Rab Ascent Down Sleeping Bag (-6°C), 2026 model
Best use
- Made for
- Backpacking and wild camping
- Not for
- Winter mountain
Why these labels
- Backpacking and wild camping: The maker states this use, and the published specs do not rule it out.
- Winter mountain: Comfort rating 0 °C: too cold for winter nights
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: 6/10 UK hills in spring and autumn. Wind, rain, and nights near freezing.
- Winter camp: 4/10 UK winter or high ground. Below freezing, strong wind, possibly snow. Capped at 4: needs warmth 9+ (comfort -5 °C or colder).
- Weight: 5/10 How much it adds to your pack, compared with the whole market.
Comfort 0 °C, limit -6 °C (ISO 23537).
Lowest price we found
£279.99 at Ultralight Outdoor Gear
Go to Ultralight Outdoor Gear Compare 3 shopsSpring-to-autumn hill camps in the UK, including nights down to light frost, for people who like room to move
- Zip
- Half
- Comfort
- 0 °C
- Limit
- -6 °C
- Fill
- 650 fill down
- Weight
- 1.2 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 £279.99 In stock. Free delivery. Shop lists the Regular at 1,145 g.
View at shop: Ultralight Outdoor GearGO Outdoors £330 In stock. Free delivery.
View at shop: GO OutdoorsRab £330 In stock. Free delivery. Regular, left or right zip, Tempest Blue.
View at shop: RabPrices 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 7/10How cold a night you can sleep comfortably through. 7: Better than most.
Rab's ISO 23537-1:2022 comfort 0 °C (limit -6 °C) sits in the -4.9 to 0 °C band. The maker's figure, not re-tested by us.
Room inside
Estimate from maker's specs: maker's shoulder girth (fewer than 3 reviews about room) 8/10How much room to move, bend your knees and sleep on your side. Roomier is comfier. 8: Clearly better than most.
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 5/10How much it adds to your pack. 5: Does the job. Average for wild-camping gear.
1,200 g (Regular, Rab's figure; one UK shop lists 1,145 g) sits in the 1,000-1,299 g band either way.
Packed size
From maker's figures 3/10How much room it takes in your rucksack. 3: Below average. Fine for some trips, not others.
Rab gives only the stuff sack size, 35 x 20 cm, so it is worked as a cylinder: 3.1416 x 10 x 10 x 35 = 10,996 cm3, so 11.0 L, in the 9-12.9 L band. Rab gives no litres.
In short
Good for
- Spring-to-autumn hill camps in the UK, including nights down to light frost, for people who like room to move
- Side sleepers and restless sleepers who find narrow mummy bags tight
Strengths
- Comfort rating of 0 °C and a limit of -6 °C, tested to ISO 23537, for 1,200 g
- Wide mummy cut with sidewall baffles, a roomy footbox and an arm-access zip
- Down is hydrophobic (water-repellent) and the shell is windproof Pertex Quantum
- Hand-filled in Derbyshire, with a UK-made bag and Rab's warranty
- Regular, Regular Wide and Long sizes, with left or right zip
Weaknesses
- 650 fill power down is a lower grade than the 800 in lighter bags, so you carry more weight for the same warmth
- Comfort 0 °C is a standard woman's figure on a good mat; cold sleepers will want a warmer bag for frost
- No independent tests of this 2026 bag yet, so damp performance, comfort and durability are estimates, not reviewed scores
- Down loses warmth if it stays soaked, so a synthetic bag is safer for persistently wet trips
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.