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.

Technical features

Features

• 850+ FILL Power, RDS-certified, Goose Down with Ultra Dry Down treatment for improved water resistance in damp conditions
• 10-Denier Nylon shell and lining. 10-Denier Nylon waterproof-breathable hood and footbox.
• Mummy Fit: Fitted cut with generous footbox and technical hood, to maximise thermal efficiency and minimise bulk and weight.
• Spark 7C/45F & 1C/30F Primary zip - 1/2 length #5 with zip-plow and two sliders. Spark -9C/15F & -18C/0F Primary zip - 3/4 length #5 with zip-plow and two sliders.
• Vertical chest baffles, horizontal baffles lower half and base. SPARK 7C sewn through quilted construction throughout. SPARK -1C/30Fbox wall baffles top half of bag and sewn through quilted construction lower half. SPARK -9C & -18C box wall baffle construction throughout.
• Spark 7C, -1C & -9C Standard front draft collar. SPARK -18C Double draft collars
• Spark 7 & -1 can't be paired. Spark -9 & -18: Pairs with Women's Sea to Summit bags.
• QuiltLock System integrates with StS quilts