Maker’s warranty: Limited lifetime warranty against defects in materials or workmanship; covers original owner, bought from Sea to Summit or an authorized reseller; paid repairs; spare parts sold. Sea to Summit’s terms, read Oct 25, 2026
A women's-specific down sleeping bag from Sea to Summit with RDS-certified 850+ fill power goose down treated with Ultra-Dry, a 10D shell and lining, and a full-length zipper that mates with a unisex Spark. The 45°F model has an ISO 23537 comfort rating of 45°F / 7°C and a lower limit of 39°F / 4°C.
Figures with a source link to the page they were read from, with the date we checked it.How we get these figures →Wrong figure? Tell us
Weight and price against the sleeping bags & quilts rated 29°F to 49°F in the RidgeNote register with a published figure; other figures against every one of the sleeping bags & quilts. Manufacturer-listed; sources and dates are on this page.
The lightest of the sleeping bags & quilts rated 29°F to 49°F on record is Zpacks Solo Quilt at 11.8 oz — 47 g less.
The cheapest is Sea to Summit Boab Synthetic Sleeping Bag at $124.00 — $225 less and 845 g heavier.
Main models on the same shelf, compared with the Spark Women's Down Sleeping Bag on the makers’ published figures; the tick on each bar is the Spark Women's Down Sleeping Bag.
Zpacks
Solo Quilt
1.7 oz lighter (47 g)
Zpacks
Classic Sleeping Bag
1.2 oz lighter (35 g)
Western Mountaineering
Nanolite Top Quilt
0.4 oz lighter (12 g)
Not ranked: 25 with no published weight.
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Kelty
Cosmic Down 20 Sleeping Bag
$159 less
1.60 lb heavier (724 g)
Sea to Summit
Hamelin Synthetic Sleeping Bag
$173 less
1.64 lb heavier (742 g)
Sea to Summit
Boab Synthetic Sleeping Bag
$225 less
1.86 lb heavier (845 g)
Not ranked: 59 with no published list price.
See all 6 →Western Mountaineering
Nanolite Top Quilt
rated 1°F warmer
0.4 oz lighter (12 g)
Zpacks
Classic Sleeping Bag
rated 9°F warmer
1.2 oz lighter (35 g)
Zpacks
Solo Quilt
rated 9°F warmer
1.7 oz lighter (47 g)
Not ranked: 25 with no published temperature rating.
See all 54 →Sleeping bags rated 15 to 25°F ranked by maker-published weight: 22 models. Lightest: Therm-a-Rest Vesper 20°F/-6°C Down Quilt at 1.21 lb (550 g).
Sleeping bags and quilts rated 26 to 35°F ranked by maker-published weight: 16 models. Lightest: Zpacks Solo Quilt at 11.8 oz (335 g). Median 1.39 lb.
How to read a temperature rating, why fill weight matters more than fill power, per-size prices, and what the makers publish for the Kelty Cosmic 20, the Western Mountaineering line, NEMO, Sea to Summit, Mountain Hardwear and Therm-a-Rest.