The Sea to Summit Spark -9°C Double Sleeping Bag is built for couples who want maximum warmth without the bulk. With a 10D nylon shell, lining, hood, and footbox, it balances lightweight packability with water resistance and breathability.

Inside, RDS-certified 850+ fill power goose down is treated with ULTRA-DRY Down™ to resist moisture, maintaining loft and insulation on damp nights. A technical mummy fit, full hood adjustment, and draft protection throughout deliver reliable thermal efficiency for cold-weather trips. 

Box wall baffle construction minimises cold spots, while vertical chest and horizontal base baffles keep down evenly distributed. A three-quarter YKK #5 zipper with dual sliders and a snag-free plow makes venting or entry easy, and down-filled draft tubes along the zip and collar help retain heat.

Rated to a comfort temperature of −2 °C with a lower limit of −9 °C, the Spark Double is a genuine sub-zero option for two. Packed into a 20L bluesign® approved compression sack, it compacts down to 14.3L for efficient carrying on ultralight missions.