Chris Townsend reviews a bag with an excellent warmth-to-weight ratio

This review was first published in the March 2018 issue of The Great Outdoors

he Neutrino 800 is the equal warmest bag tested but it weighs 400 grams less than the Couloir 1000 due to the higher fill power down and the lighter weight shell fabric. For the warmth it’s very light. The down is hydrophobic too, using a treatment developed with Nikwax. The Pertex Quantum shell allows the down to loft fully.

The hood is excellent. There’s a warm adjustable internal collar and a good baffle behind the two-way zip. Comfort is excellent, the bag being narrow enough to cut out cold spots but still with enough room to move inside. I could wear a light down jacket inside though I can’t imagine ever needing to do so. At -12.6°C I was very warm inside wearing just thin base layers. Indeed, my feet in medium weight wool socks were rather too hot. For cold sleepers this could be the ideal winter backpacking bag. It is expensive but I doubt there’s anything lighter that’s this warm.

Rab uses down that’s traceable under the European Down & Feather Association Codex, which ‘ensures that the down does not come from birds that have been live-plucked or force-fed and that their welfare has been protected from the time they were hatchlings to when they are slaughtered’.