Kelty
Cosmic 20 Sleeping Bag (Long)
Best three-season mummy bag for taller backpackers seeking reliable, cozy warmth.
Designed for three-season adventures, this mummy-style sleeping bag offers reliable warmth and comfort in a fully recycled package. The thermally efficient construction utilizes synthetic insulation to maintain heat, while the offset quilt design eliminates cold spots for a consistent sleeping experience. A spacious, natural-fit footbox allows for comfortable movement, and the draft-blocking collar and tube ensure warmth stays trapped inside. With buttery-soft fabrics and a convenient internal stash pocket for small essentials, this bag provides a cozy, lightweight solution for backpacking trips, ensuring you stay comfortable from dusk until dawn in varying outdoor conditions.
$109.95
More Cosmic Options
Cosmic 20
$159.95
Cosmic Down 20
$189.95
Cosmic 40
$119.95
Cosmic Synthetic 0 Degree
$139.95
Cosmic Synthetic 20 Degree
$119.95
Cosmic Synthetic 20
$109.95
Cosmic 20 Degree Sleeping Bag
$159.95
Cosmic Ultra 20 Degree
$269.95
Cosmic
$314.95
Cosmic 20 Sleeping Bag
$118.22
Cosmic Ultra 0°F Sleeping Bag
$219.95
Cosmic Ultra 800 DriDown Sleeping Bag
$184.48
Cosmic 0 Synthetic Sleeping Bag
$129.95
Cosmic 20 Sleeping Bag
$118.22
Cosmic Ultra 0°F
$245.97
Kelty Cosmic 20
$169.99
Kelty Cosmic Synthetic 0 Degree Sleeping Bag
$166.00
Kelty Cosmic Down 20
$189.95
Kelty Cosmic Ultra 0
$369.95
Cosmic Synthetic 40 Degree
$99.95
Cosmic Synthetic 20
$109.95
Owner Satisfaction
4.5
/ 5
Category Rank
1010
/ 2020
#1010 in Sleeping Bags
Price vs Category Average
-34%
Below average
Temperature Rating
20
/ °F
Who it's for
- Budget-conscious campers wanting premium down warmth
- Backpackers needing to save space and weight
- Three-season campers exploring moderate climates
Who should skip it
- Campers who dislike finicky gear adjustments
- Minimalists requiring the smallest possible packed size
- Ultralight hikers prioritizing maximum warmth-to-weight efficiency
Performance breakdown
Thermal Efficiency
Offset quilt construction and draft tubes effectively lock in core warmth.
Weight-to-Warmth Ratio
Synthetic insulation adds bulk compared to down but remains reliable.
Interior Roominess
Natural-fit footbox provides generous space for restless sleepers to move.
Zipper Performance
Quad-stitch anti-snag design makes midnight exits smooth and frustration-free.
Packability
Synthetic fill requires significant compression to fit into smaller packs.
Weather Resistance
PFAS-free DWR coating handles damp conditions without compromising environmental safety.
Key Specs
Temperature Rating
20°F
Weight
3.19 lbs
Max User Height
78 inches
Sleeping Bag Shape
Mummy
Insulation Type
Synthetic
Shell Material
Nylon
Lining Material
Polyester
Season Rating
3-Season
Know before you buy
The Cosmic 20 is rated for three-season use, meaning it is designed to keep you comfortable in temperatures down to roughly 20°F. It features an offset quilt construction to eliminate cold spots and an upper draft collar to help trap your body heat inside.
The CirroLoft ECO synthetic insulation is made from 100% recycled fibers and is designed to mimic the warmth and compressibility of down. While it is slightly heavier than down, it retains its insulating properties even if it gets damp, making it a reliable choice for humid or unpredictable climates.
The Long version is specifically sized for individuals taller than the standard model, typically accommodating users up to 6'6". It provides extra length to ensure you aren't compressing the insulation at your feet or head, which helps maintain the bag's thermal efficiency.
Kelty has included an anti-snag treatment on the zipper track to prevent the fabric from catching. Additionally, the dual locking sliders allow you to vent the bag from the bottom if you get too warm during the night.
Yes, the bag features an expanded, natural-fit footbox designed to give your feet more room to move. This shape is less restrictive than traditional mummy bags, allowing for a more natural sleeping position.
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