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Sea to Summit Alpine Down Sleeping Bag -29°C

Size: Regular

This 4-season Sea to Summit Alpine -29°C down mummy sleeping bag boasts top-grade Ultra-Dry goose down and a perfectly shaped mummy design for optimal insulation. Designed for extreme cold weather conditions, it offers 850+ FILL Power and ample space for extra winter gear, providing confidence and peace of mind for your outdoor adventures. You can also form a snug double sleeping bag by zipping to any women's sleeping bag from Sea to Summit or you can combine this with a quilt for added warmth. A STS REegular Pillow will also fit neatly inside the hood.

Pair up your Sea to Summit sleeping bag with a compatible liner for the ultimate sleep system. Sleeping Bag Liners

More Help? For further assistance on choosing your down sleeping bag, we have an article explaining fill power, the pros and cons of down over synthetic insulation and more info on caring for your bag available to view here: A Guide to Down Sleeping Bags.


  • ULTRA-DRY Down 850+ Loft 90% Down Cluster Premium Goose Down certified.
  • Responsible Down Standard (RDS).
  • Free-flow zipper system: one full-length YKK® #5 main zip and a half-length zip on the opposite side for ventilation.
  • Expedition fit sizing gives you room to wear extra clothing and accommodate gear inside the bag that you don't want to freeze!
  • Anatomically-shaped, oversized foot box can accommodate boot liners.
  • Generous fitted hood with two soft touch adjustments. Fits a Sea to Summit regular pillow.
  • Double draft collars: fitted front collar and tubular back
  • Internal pocket for phone / GPS / valuables.
  • QuiltLock: Every Sea to Summit sleeping back features the QuiltLock system that uses the snap locks located at the shoulder and foot end of Sea to Summit sleeping bags plus the quilt footbox / quilt straps to secure a quilt to the sleeping bag. This adds thermal performance and versatility to your sleep system: your integrated Sea to Summit quilt now works for ultralight summer adventures and turns your three-season bag into a four-season sleep system.
  • Includes lightweight Ultra-Sil compression bag and storage cell.


    • Maximum User Height:  Regular: 185cm /  - Long: 198cm
    • Comfort Temperature: -19°C
    • Comfort Temperature limit:  -29°C
    • Shoulder width:  Regular: 160cm / Long: 170cm
    • Waist With: Regular: 149cm / Long: 159cm
    • Foot box width:  Regular: 122cm / Long: 132cm
    • Insulated collar: Yes
    • Shell Fabric: Recycled 20-Denier Nylon shell and lining. 10-Denier Nylon waterproof-breathable hood and footbox.
    • Filling: Ultra-Dry goose down
    • Fill power: 850+
    • Weight: Regular: 1459g / Long: 1645g
    • Fill Weight: Regular: 1000g / Long: 1135g
    • Compression Size: 26L
    • Zip: Left

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