Alpine Down Sleeping Bag for High Altitude and Colder Latitude Adventures

Gear up for your next high altitude or colder latitude adventure with the Alpine Down Sleeping Bag. Filled with 850+ fill power goose down treated with PFAS-free Ultra-Dry Down, it stays warm and lofty even in damp alpine conditions. The roomy expedition mummy fit leaves space for performance clothing and essential gear, while the Free-Flow Zip system gives you control over ventilation. Built with complex construction and durable materials, it is made for mountaineering and harsh winter use where reliability matters most.

Features

• 850+ Fill Power Goose Down: Each 30g of down expands to 850 cubic inches, giving exceptional warmth-to-weight efficiency.
• Ultra-Dry Down Treatment (PFAS-free): Hydrophobic coating absorbs less moisture, dries faster, and keeps loft even in damp alpine conditions.
• Recycled 20D Nylon Shell: Lightweight, durable, and coated with PFAS-free DWR to protect against condensation inside tents.
• Expedition Mummy Fit: Roomy cut offers extra space for insulated clothing or gear.
• Free-Flow Zip System: Full-length zipper plus a half-length opposite zip for multiple ventilation options.
• QuiltLock Compatibility: Snap closures allow you to attach Sea to Summit quilts for extra versatility, turning a three-season bag into a four-season system.
• Breathable Liner: Promotes comfort and reduces condensation inside the bag.
• Technical Hood and Footbox: Maximises warmth retention where you need it most.
• Generous Draft Tubes: Runs along the zippers to block out cold air.
• Lifetime Guarantee from Sea to Summit.

Performance

• Weight: 1.645 kg (Long)
• Compressed Volume: 14 L (Long)
• Temperature Rating: -29°C ISO Lower Limit | -19°C ISO Comfort
• Packability: Compact with included 40D recycled bluesign® approved compression bag
• Best Use: Mountaineering and extreme cold expeditions

Tech Specs

• Shape: Expedition mummy
• Insulation: RDS-certified 90/10 Goose Down, 850+ fill power, PFAS-free Ultra-Dry treatment
• Shell: 100% recycled 20D nylon with PFAS-free DWR
• Lining: 100% nylon
• Stuff Sack: 100% nylon (excluding trims)
• Fill Weight: 1135 g (Long)
• Fits Up To Height: 198 cm (Long)