Sea to Summit Ascent Down Sleeping Bag 15-Degree Long – Three-Season Backcountry Comfort

Meet the Sea to Summit Ascent: a versatile, three-season down sleeping bag built for backcountry adventures

The Ascent blends warmth, adaptability, and lightweight durability. With 750+ fill power goose down and an Ultra-Dry treatment, it aims to stay drier in damp conditions while delivering reliable warmth when nights cool down. The hood, draft-tube protected zippers, and an intelligently crafted fit work together to reduce drafts without compromising comfort.

When conditions rise or you find yourself in milder nights, the Free Flow Zip System opens the bag into multiple configurations. You can unzip for ventilation, lay it flat to function as a quilt, or adjust the setup to suit your comfort level. This flexibility positions the Ascent as a strong option for three-season trips, from alpine approaches to late-summer campouts.

Configurations and real-world use

• In cold weather, cinch the hood and seal the draft-tube zippers to trap heat and enjoy a thermally efficient, relaxed mummy fit.
• In warmer nights, unzip sections or open fully to create airflow or use as a quilt for added comfort.
• The bag can zip with a compatible Sea to Summit Women’s bag for shared space, ideal for couples or sharing a bivy.

Materials, warmth, and durability

• Lightweight 20D recycled nylon shell with a non-PFC DWR finish protects against wind and moisture; a 20D recycled nylon liner adds comfort.
• RDS-certified 750+ fill goose down with Ultra-Dry Down helps maintain warmth and resists dampness, with down stay-in-place box baffles and vertical torso baffles.
• Designed for rugged use with a lifetime Sea to Summit Guarantee, reinforcing durability for the long haul.

Whether you’re chasing crisp nights in the mountains or damp, wind-prone campsites, the Ascent is designed to adapt without feeling bulky. It’s a practical option for hikers, climbers, and campers who value warmth, airflow, and versatile sleeping configurations without sacrificing ease of use. Note that the product is described as a 15-Degree bag; actual comfort will depend on your sleep system, clothing, and surrounding conditions.