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Rab Neutrino Pro 400 sleeping bag review: pretty much perfect

The Rab Neutrino Pro 400 is a reassuringly snug sleeping bag designed for climbers tackling fast-and-light mountain missions – also the perfect three-season camping cocoon

Rab Neutrino Pro 400
(Image: © Rab Neutrino)

Our Verdict

The Rab Neutrino Pro 400 strikes the ideal balance between warmth and weight, which makes this our top pick if you’re after a solid three-season down sleeping bag.


  • Comfortable
  • Packable
  • Lightweight
  • Warm


  • Expensive

First impressions

Rab’s most recent marketing tagline trumpets the brand as ‘masters of insulation’. That’s a pretty bold claim, but the Rab Neutrino Pro 400 has the specs to back it up.

It’s filled with high-quality 800 fill power goose down that offers impressive warmth-for-weight as well as packability, reflecting its intended use as a specialist mountaineering piece, where every gram and cubic inch counts.

However, it’s too good a sleeping bag to be reserved solely for elite climbers, particularly since so many of the features that enable the Pro to excel in high alpine environments mean it is also brilliant for backpackers and wild campers too.

That applies even in damp UK weather, since hydrophobic fill and a water-resistant shell makes it far more resistant to moisture than most down bags.


RRP: £355 (UK)
Weight: 819g/1lb 13oz
Length: 190cm/75in (regular) / 205cm/81in (long)
Max user height: 185cm/6ft 1in (regular) 200cm/6ft 6.5in (long)
Packsize: 36x19cm (14-7.5in) Fill: Ethically sourced/ certified European Goose Down
Comfort: -1°C/30°F
Limit: -7°C/14°F
Compatibility: 3-season

In the field

We really appreciated the Neutrino Pro’s generous length and extra room for the upper torso, and so too will anyone who is over six foot or slightly broader of chest. 

The bag tapers to a contoured footbox, which leaves less room for the lower limbs, but this is still a comfortable bag to lie in. It’s also very cosy, thanks to a shaped hood and contoured footbox, plus chunky zip and collar baffles.

We were impressed by the bag’s meticulous design and excellent quality of construction too – Rab have clearly thought carefully about how to build the best bag possible within the parameters of weight and packability. For example, the down chambers are arranged in chevrons, which helps to hold the fill over the centre of the body and prevent it from migrating (which often causes cold spots).

Similarly, we loved this bag’s extra little details, like the handy internal stash pocket and the ‘noctilucent’ zip puller – which means it glows in the dark to you and me. The practical roll-top stuff sack compresses well too, ensuring it packs easily into a rucksack. In fact, for us, this is pretty much the perfect three-season bag.