Sea to Summit Spark Pro Ultralight Down Sleeping Bag - 15°F, Long

Sea to Summit Spark Pro Ultralight Down Sleeping Bag — 15°F, Long

Designed for alpine trails, bike routes, and backcountry treks, the Spark Pro blends serious warmth with minimal weight. The Long version, rated for 15°F (-9°C), delivers dependable warmth in three-season conditions while packing down small enough to ride on a minimalist frame or into a compact backpacking setup. With a premium 950+ fill power goose down (RDS certified) and a proprietary Ultra-Dry Down treatment, this bag aims to retain loft and keep you comfortable when moisture enters your camp routine. The contoured mummy shape, hood, and draft collar work together to minimize heat loss without cramping your sleeping position.

The Spark Pro’s shell is built from featherweight 10D nylon with a PFC-free DWR finish, helping shed light moisture and wind while remaining breathable against skin. The 10D liner enhances comfort and improves air movement inside the bag. Zipper performance is prioritized with a snag-free YKK #5 side zipper (plus a lighter #3 zipper at the shoulder/foot for reduced bulk). A versatile Free Flow Zip system allows you to vent warmth when temps rise and even open the bag flat as a quilt for warm, relaxed evenings in camp.

Warmth, Fit, and Construction

• Contoured mummy silhouette with a hood and neck draft collar to minimize heat leakage
• 15°F bag uses full box baffles to maximize warmth in the torso and limbs
• 950+ fill power down with Ultra-Dry treatment improves resilience in damp or humid nights

Materials, Breathability, and Weather Resilience

• Featherweight 10D nylon shell with a PFC-free DWR finish protects the hood and footbox
• Breathable 10D liner supports comfort and reduces clamminess during longer nights
• YKK zippers with a plow for snag-free operation and efficient venting

Packability, Sizing, and Warranty

Available in Regular and Long to suit taller sleepers, the Spark Pro prioritizes compact packing without compromising warmth. It includes an Ultra-Sil compression sack and a storage cube for neat home storage. Sea to Summit backs the bag with a lifetime guarantee against defects in materials or workmanship, offering reassurance for rugged outdoor use.