Kelty Supernova 20

The Kelty Supernova 20 is a duck-down sleeping bag rated to a -7°C limit temperature, weighing 1360 g in the same semi-rectangular, roomier cut as the rest of the Supernova line. It shares the recycled-fabric lining, opens flat as a blanket, and can zip together with another Supernova bag to form a double. Its warmth-to-weight ratio is listed at 5.1, or 194.3 g per degree of rated warmth — a notably more efficient figure than the milder 4°C-rated Supernova in the same line (240 g per degree), since reaching a colder limit temperature packs in more insulation for each added gram. The semi-rectangular shape still trades some thermal efficiency for room to move compared with a snug mummy cut, and duck down keeps the price down relative to higher fill-power alternatives. Rated to -7°C, this is a bag for shoulder-season nights and colder three-season camping, worth the extra weight and bulk over a milder-rated bag if your trips regularly dip below freezing.