The Kelty Cosmic Down 20 is a three-season mummy bag built in Kelty's Short size, fitted for users up to 168 cm, with a men's-specific cut through the shoulders and hips. Manufacturer-rated to 0°C comfort and -6°C limit (with an extreme rating down to -24°C), it uses 415 g of 550-fill-power DriDown duck down — treated to resist moisture the way standard down doesn't — inside a recycled 20D nylon shell with trapezoidal baffles that spread fill more evenly than sewn-through construction.
At 1.06 kg total, it's noticeably lighter than Kelty's colder-rated Cosmic Down 0, which makes sense given the smaller size and higher (less extreme) temperature rating rather than any change in insulation quality. A full draft collar and draft tube seal in warmth at the neck and zipper, and an internal pocket holds small items like a headlamp or phone. Being manufacturer-rated rather than independently lab-tested, actual comfort in the field may run warmer or colder than stated depending on individual metabolism.
Specifications
Comfort Temperature
0 °C
Limit Temperature
-6 °C
Extreme Temperature
-24 °C
Temperature Rating Standard
Manufacturer rated
Season Rating
3-season
Total Weight
1060 g (2.34 lb)
Fill Weight
415 g (14.6 oz)
Internal Length
183 cm (6.0 ft)
Packed Size ( Length x Diameter )
33 x 18 (1.1 x 7.1 ft)
Insulation Type
Duck down
Fill Power
550
Hydrophobic Down
✓
Shape
Mummy
Baffle Construction
Trapezoidal
Baffle Orientation
Horizontal
Two-Way Zipper
✓
Shell Fabric
Recycled 20D Nylon Taffeta
Liner Fabric
Recycled 50D Polyester Taffeta
Draft Collar
✓
Draft Tube
✓
Internal Pocket
✓
Size Category
Short
Maximum User Height
168 cm (5.5 ft)
Gender-Specific Fit
Men's specific
Recycled Materials
✓
PFC/PFAS Free
✓
Warmth-to-Weight Ratio f(x)
5.7 °C/kg
Fill Efficiency f(x)
1.45 °C/100g
Weight per Degree f(x)
176.7 g/°C
Bag Type
Mummy sleeping bag
Where to buy
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Category context Sleeping Bags (417 products)
Weight
Standard weight· mainstream zone 819–1420 g· ranked 198 of 418