Sea to Summit Ascent Down Sleeping Bag 30-Degree, Long | 3-Season Comfort & Ventilation

Three-season versatility with adaptive warmth

The Sea to Summit Ascent Down Sleeping Bag is built to cover a wide range of backcountry nights. With 750+ fill power goose down and an Ultra-Dry Down treatment, you’ll notice warmth when the temperature drops and drier performance in damp conditions. In warmer weather, the bag folds into flexible configurations that encourage airflow and comfort, making it a reliable companion for camps, huts, or weekend treks.

Key configurations for varying conditions

• Free Flow Zip System lets you unzip for generous ventilation or seal for snug warmth.
• Thermally efficient mummy cut provides room in the hood and around the chest while staying lightweight.
• Hood accepts an Aeros pillow and can pair with a compatible Sea to Summit women’s bag for a two-person setup when needed.
• In cold nights, cinch the hood and seal the draft tube to help maintain warmth without extra bulk.

Smart construction for dryness, warmth, and longevity

• RDS-certified 750+ fill power goose down with a non-PFC Ultra-Dry Down treatment helps stay drier in damp conditions.
• Lightweight 20D recycled nylon shell with non-PFC DWR provides wind resistance and moisture protection;
• 20D recycled nylon liner adds a soft, comfortable feel against the skin.
• Box-baffle design with vertical torso baffles minimizes down shifting and maximizes warmth retention.

Practical camp-ready features that adapt to your plans

In warmer nights you can open the bag flat to use it as a quilt, or unzip the footbox for extra venting. The design also supports acting as a breathable layer around camp, with snaps at the shoulders for comfortable wear during transitions between sleeping and lounging. The Sea to Summit Guarantee backs the product for the lifetime of use, underscoring durability and service.

Three-season backcountry reliability — a blend of clever design, quality materials, and thoughtful details that help you focus on the adventure, not the gear.