Rab
Rab Radeon Synthetic Sleeping Bag (-6°C)
Best use
- Made for
- Backpacking and wild camping
- Not for
- Bikepacking, Winter mountain
Why these labels
- Backpacking and wild camping: The maker states this use, and the published specs do not rule it out.
- Bikepacking: Bulky for bike bags: packs to 15.2 litres
- Winter mountain: Comfort rating 0 °C: too cold for winter nights
From the maker's stated use and the published specs.
- Summer wild camp: 4/10 UK, roughly May to September, nights above about 8 °C, sheltered pitches.
- Three-season hills: 5/10 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: 4/10 How much it adds to your pack, compared with the whole market.
Comfort 0 °C, limit -6 °C (ISO 23537).
Lowest price we found
£144.99 at Ultralight Outdoor Gear
Go to Ultralight Outdoor Gear Compare 3 shopsSpring-to-autumn UK camps where nights drop to light frost and tents run damp with condensation
- Comfort
- 0 °C
- Limit
- -6 °C
- Fill
- synthetic
- Weight
- 1.31 kg (Regular)
Packed size 15.2 L, 40 cm long and 22 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 £144.99 In stock. Free delivery. Regular size, 5 in stock when checked.
View at shop: Ultralight Outdoor GearRab £170 In stock. Free delivery. Regular, right zip in stock; Regular left zip and the Long sizes out of stock on the check day.
View at shop: RabTiso £170 In stock. Free delivery.
View at shop: TisoPrices 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.
Maker's ISO 23537 comfort 0 °C (limit -6 °C, extreme -24 °C) sits in the -4.9 to 0 °C band: spring and autumn with light frost, not winter.
Room inside
Estimate from maker's specs: bag shape (fewer than 3 reviews about room) 5/10How much room to move, bend your knees and sleep on your side. Roomier is comfier. 5: Does the job. Average for wild-camping gear.
No review we found says how roomy it is, so this is an estimate from the bag shape.
Weight
From maker's figures 4/10How much it adds to your pack. 4: A bit below average.
Rab's 1,315 g for the Regular sits in the 1,300–1,699 g band. Ultralight Outdoor Gear lists 1,293 g, which would be the 3 band; we use the maker's figure.
Packed size
From maker's figures 1/10How much room it takes in your rucksack. 1: A real weak point.
Rab gives 22 x 40 cm with no labels. As a stuff sack of 22 cm across and 40 cm long: 3.1416 x 11 x 11 x 40 = 15,205 cm³, so 15.2 L, in the 13 L+ band. The other way round would be bigger still, so the band is the same.
In short
Good for
- Spring-to-autumn UK camps where nights drop to light frost and tents run damp with condensation
- Side sleepers who want a roomier cut (a Wide size is also sold)
Strengths
- Maker's comfort rating of 0 °C with a -6 °C limit, ISO 23537 rated
- Synthetic Stratus fill: Rab says it keeps insulating when damp and dries quickly, so it is less worried by a wet night than a down bag
- Two-way 3/4 zip, insulated zip baffle and hood drawcord let you vent or seal up
Weaknesses
- Heavy at 1,315 g, which is a weak score for weight
- Bulky: about 15 L packed in its compression sack
- No independent review of this exact bag found, 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.