The Spark Ultralight Mummy Sleeping Bag Series spans everything from an ultralight down-filled liner, to a mid-winter fast-and-light sleeping bag. Each model uses premium materials and no-frills design to provide cutting-edge performance.

Ultralight does not mean ultra-tight: The Spark mummy sleeping bags are snug but still have adequate wiggle room for the performance-oriented, backcountry user.

Get the best out of your new Sleeping Bag click here for sleeping bag care instructions.

ULTRA-DRY Down 850+ Loft 90% Down Cluster Premium Goose Down certified Responsible Down Standard (RDS)
10D shell and 7D liner materials help to achieve the incredible lightweight and compact packed size
Includes lightweight Ultra-Sil compression bag and storage cell

Zipper-length trimmed for gram-saving performance:

50°F, 40°F, and 28°F have 1/3-length zippers
18°F and 5°F have full-length side zippers that can be coupled to a Flame sleeping bag with a full-length zipper

Baffle construction:

50°F and 40°F have sewn-through construction
28°F has baffles in the torso and sewn through in the leg area
18°F and 5°F are fully baffled

Shape:

50°F , 40°F and 28°F - Contoured mummy
18°F and 5°F - Broader mummy

BEST USE: Ultralight Backpacking

PERFORMANCE: Warm Weather

WEIGHT: 12oz | 340g

COMPRESSED VOLUME: 1.5 liters

LOWER TEMP RATING: 40ºF | 5ºC

Sea To Summit Spark Ultralight Down 40 Degree Sleeping Bag