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.

Features

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:

10°C, 5°C, and -2°C have 1/3-length zippers
-8°C and -15°C have full-length side zippers

Baffle construction:

10°C and 5°C have sewn-through construction
-2°C has baffles in the torso and sewn through in the leg area
-8°C and -15°C are fully baffled

Shape:

10°C , 5°C and -2°C - Contoured mummy
-8°C and -15°C - Broader mummy

Sea to Summit Patents