Best Overall
Kelty Cosmic 20
Key details
- Fill
- 550-fill down
- Weight
- 2.6 lb
- Dimensions
- 78 in L x 30 in W
- Temperature Rating
- 20°F
A 20°F rating and 550-fill down are the two numbers that make the Cosmic 20 worth the money. Down is the reason this bag compresses smaller than the synthetic bags here, and at 2.6 pounds it disappears into a pack in a way a three-pound-plus bag does not. The recycled shell and PFAS-free DWR are nice extras, not the reason to buy.
What sold us is the balance: this is the lightest bag in this group that still carries a real three-season rating. We tested it against the budget mummies, and the difference shows up in packed bulk more than in the temperature number. The 78-inch length fits sleepers up to about six feet, and the mummy shape keeps dead space down. Broad-shouldered sleepers should take the 30-inch width seriously, though; we found it snug across the chest.
The shell is a recycled 20D nylon taffeta with a soft polyester lining, and it feels light without feeling disposable. The down is traceable and RDS certified, which is the kind of detail we like to see on a bag at this price. The included stuff sack is adequate, though a separate compression strap will get the bundle smaller for a tight pack.
On a week-long trip, the packed bulk is what you notice: it leaves room for food and a puffy layer, which is the point of paying for down. For a backpacker who wants one bag for spring through fall, that is the advantage that matters.
Pros
- 20°F down warmth for three-season trips
- 2.6-pound weight packs small
- Recycled shell and RDS-certified down
Cons
- Premium price compared with synthetic bags
For three-season backpacking, the Cosmic 20 is the bag we recommend: 20°F of down warmth at 2.6 pounds, with a packed size that leaves room for the rest of your kit.