The Quantum range is designed to give the best warmth-to-weight ratio, and this 3-season down sleeping bag does not disappoint. The Tundra bag is 139g lighter, but it has a comfort temperature of +2 deg C, which is not much competition for the Rab’s -7 deg C. Best-quality materials ensure the bag feels really soft and cosy, while the light Pertex fabric means a small packed size, making it an ideal choice for trips where weight, warmth and size are issues. Functional features include baffles along the zip and round the neck, all helping to keep out draughts, and being a women’s fit, the chest width is on the narrower side. But the lightweight fabric on this bag gets easily caught in the zip, making those midnight trips to the loo even more of a mission. Similarly the elastic used for the drawcords is lumpy, making it hard to slide through the cord lock – and with a price tag of £250 this should not be the case.
Outer fabric: Pertex Quantum
Inner fabric: Pertex Quantum
Insulation: 400g of 96% white goose down, 750+EU/850+US fill power
Construction: narrow precurved box wall
Packed size: 32x19cm
Made in: UK
Stores in the UK: 19
Verdict: If you want maximum warmth for weight, Rab is still way ahead, but the snagging zip and hood drawcords are annoying.