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Sea to Summit Spark SpI Down Sleeping Bag (+4C)

Sea to Summit Spark SpI Down Sleeping Bag (+4C)
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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 for the designed end-use.

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

Weight - 340g / 12oz (regular size)
Fill - 850+ Fill Power Ultra Dry RDS Goose Down
Fil Weight: 180g / 6.35oz

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

1/3-length zipper

Sewn-through Baffle construction

Recommended Use

Ultralight Backpacking


Summer/Warm Weather  

Temperature Rating


Comfort Limit


Lower Limit




Insulation Type

850+ Fill Power Ultra Dry


RDS Goose Down

Bag Weight

Regular: 340g / 12oz


Long: 385g / 13.6oz

Fill Weight

Regular: 180g / 6.3oz


Long: 205g / 7.2oz

Fits to User Height

Regular: 183cm / 6ft


Long: 192cm / 6’4”

Girth – Shoulder

Regular: 148cm / 58”


Long: 152cm / 60”

Girth - Hip

Regular: 126cm / 50”


Long: 132cm / 52”

Girth - Foot

Regular: 88cm / 35”


Long: 94cm / 38”

Stuff Sack Size

10 x 23cm / 4 x 9”

Compressed Volume

Regular – 1.5L


Long – 2.2L

Fabric – Shell

Ultralight 10D Nylon Shell

Fabric – Lining


Comes With

Ultra-Sil Compression Sack


Storage Cell


Sea to Summit Spark Series Sleeping Bags