Kelty
Cosmic Ultra 800 DriDown Sleeping Bag
Best lightweight option for backpackers seeking warmth on a budget.
Designed for cold-weather excursions, this sleeping bag utilizes high-loft hydrophobic down to ensure warmth even when conditions turn damp. The mummy silhouette and specialized baffle construction work together to trap heat efficiently, while the eco-conscious water-repellent finish adds a layer of protection against the elements. With a spacious footbox and convenient storage options, it balances technical performance with comfort for winter and shoulder-season adventures. The internal stash pocket keeps small essentials secure, while the anti-snag draft tube ensures smooth operation and prevents heat loss throughout the night.
$184.48
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Cosmic Synthetic 20
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Owner Satisfaction
4.4
/ 5
Category Rank
1514
/ 2020
#1514 in Sleeping Bags
Price vs Category Average
-35%
Below average
Material
200
/ D nylon with C and PFC-free DWR coating
Who it's for
- Backpackers seeking premium warmth without the typical high-end price tag
- Cold sleepers who need consistent thermal coverage during chilly mountain nights
- Hikers prioritizing ergonomic comfort and toe warmth during extended trips
Who should skip it
- Ultralight enthusiasts aiming for the smallest possible pack volume
- Campers who prefer effortless, one-handed zipper operation in the dark
- Side sleepers or larger individuals who require extra internal wiggle room
Performance breakdown
Thermal Efficiency
Trapezoidal baffles and 800-fill down create a formidable barrier against freezing temperatures.
Moisture Management
Hydrophobic down and PFC-free coating handle damp conditions with impressive reliability.
Weight-to-Warmth Ratio
Solid insulation density provides substantial winter warmth without excessive pack weight.
Interior Comfort
Natural-fit footbox offers welcome roominess for restless sleepers in a mummy bag.
Zipper Reliability
Anti-snag draft tube design ensures smooth operation during middle-of-the-night exits.
Feature Integration
Thoughtful internal stash pocket keeps essentials secure and within easy reach.
Key Specs
Material
20D nylon with C0 and PFC-free DWR coating
Insulation
800-fill DriDown
Shape
Mummy
Zipper
Full-length
Max User Height
78 inches
Temperature Rating
0 degrees Fahrenheit
Comfort Rating
18 degrees Fahrenheit
Lower Limit Rating
5 degrees Fahrenheit
Know before you buy
The 0-degree rating is the survival limit, meaning it is designed to keep you alive in those conditions. For a comfortable night's sleep, look at the comfort rating of 18 degrees Fahrenheit, which is the temperature at which an average sleeper will feel warm and relaxed.
DriDown is treated with a water-repellent finish that helps the down clusters resist moisture and retain their loft better than untreated down. While it isn't waterproof, it keeps you warmer for longer if you encounter condensation or damp conditions in your tent.
The Cosmic Ultra 800 features a natural-fit footbox and a generous shoulder circumference of 64.2 inches, which is designed to offer more room than a traditional, tight-fitting mummy bag. However, if you are a side sleeper who prefers significant room to sprawl, you may still find the tapered shape snug.
Yes, the bag uses a C0 and PFC-free DWR coating. This eco-conscious finish provides reliable weather resistance without the use of harmful perfluorinated chemicals.
Yes, there is an internal zippered stash pocket specifically designed to keep small essentials like your phone, headlamp, or batteries secure, warm, and within reach throughout the night.
The draft tube runs along the zipper to prevent cold air from leaking through the zipper teeth, which is a common weak point in sleeping bags. The anti-snag design ensures you can zip and unzip smoothly without catching the fabric, making it easier to get in and out quickly.
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