Kelty Cosmic Synthetic Sleeping Bag 20F
- 20 degree rating, mummy backpacking bag
- Cirroloft synthetic insulation, polyester fill
- Nylon taffeta shell, polyester taffeta lining
- Stuff sack and compression straps included
- Zipper closure, one person
- PFC-free fabrics, limited lifetime warranty
Last refreshed Sep 28, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A synthetic mummy bag for backpacking that packs down with its compression sack. The listing names two different season ratings, so rely on the stated temperature rating.
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ASIN: B0DPNKCY4FModel: Cosmic Synthetic 20Category: Sleeping Bags
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Overview
Cirroloft synthetic insulation supplies the warmth in this Kelty mummy bag, and a compression stuff sack shrinks it for the pack. A soft taffeta lining and a zipper closure complete the one-person design.
Compressible synthetic warmth in a lightweight bag is the reason to consider it for trail trips. The limitation is the missing detail around the temperature rating: the listing does not say whether it is a comfort or a limit rating, and it mixes season labels.
Who it's for
Hikers who carry their sleep system and want it to pack small will use the compression straps and stuff sack. Cold-weather campers, anyone over the listed height and those wanting a wide bag should look at other sizes.
Pros and cons
- Compressible synthetic insulation
- Stuff sack and straps included
- Soft taffeta lining
- Limited lifetime warranty
- Season rating conflicts in listing
- Temperature rating type not stated
- Mummy shape is narrow
Performance notes
The synthetic fill holds warmth between the shell and the lining, while the mummy shape reduces dead air around the sleeper. The compression straps and stuff sack set how small the bag packs.
Specifications
| Brand | Kelty |
|---|---|
| Model | Cosmic Synthetic 20 |
| Dimensions & fit | |
| Maximum Height Recommendation | 6 feet |
| Size | Long |
| Item weight | 1.61 kg |
| Item Dimensions L x W | 72 x 28 inches |
| Capacity & performance | |
| Temperature Rating | 20 degrees |
| Construction & materials | |
| Fill Material Type | Polyester, Cirroloft synthetic insulation |
| ShellMaterial | 380T nylon taffeta |
| Fabric Type | 50D 300T polyester taffeta |
| Color | Dark Blue |
| Included components | |
| Included Components | Compression Straps, Sleeping Bag, Stuff Sack |
| Warranty & support | |
| Warranty Description | Kelty Limited Lifetime Warranty |
| Other details | |
| Occupancy | 1 Person |
| Shape | Mummy |
| Closure Type | Zipper |
| Seasons | All Seasons (description says three-season) |
Frequently asked questions
Will the Kelty Cosmic Synthetic 20 fit a tall camper?
It is the long size at 72 by 28 inches, with a maximum height recommendation of 6 feet.
What comes with the Kelty Cosmic Synthetic 20?
The sleeping bag, a stuff sack and compression straps.
Is it a double bag?
No. It is a one-person mummy bag.