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Star Fire Ul -20˚ Sleeping Bag

Big Agnes

Star Fire Ul -20˚ Sleeping Bag


Online inventory may not reflect in-store availability.

Star Fire Ul -20˚ Sleeping Bag is available to buy in increments of 1

These technical, ultralight bags are designed for adventures where every ounce counts, each nook and cranny in your pack is accounted for, and you depend on the performance of your sleeping bag like you would a harness, helmet, or beacon. The "Fly Creek of sleeping bags," our Star Fire UL series features the ultimate 850 fill power DownTek™ water-repellent down, and are built with a superlight, high-tear strength shell that also protects the inside footbox. Body-mapped baffle construction optimizes thermal efficiency creating the lightest, highly compressible bag for your most remote of overnight adventures. 

Construction and Materials

  • Shell and lining are Pertex® Quantum nylon rip-stop 
  • 100% recycled Pertex® Quantum uses a tightly woven structure made from incredibly fine yarns, making a light and soft fabric that allows insulation to fully loft and maximize thermal efficiency
  • 850 fill DownTek™ repels water while maintaining insulating value - bluesign® Certified PFOA and PFOS free water repellent chemistry
  • Insotect Flow™ vertical baffles contour to your body to provide a more comfortable fit and keep you warmer


  • Ultralight down mummy bags that feature 850 fill power 
    DownTek™ down and a Pertex® shell to create our most compressible, technical bags
  • Traditional mummy shape allows for lightweight and increased thermal value
  • Body mapped baffle construction optimizes thermal efficiency
  • 3-D anti-snag draft tube prevents heat loss along the zipper
  • Vertically structured sidewalls integrating contoured baffles trap heat closer to the body
  • Contoured hood baffles cradle the head for a more comfortable fit
  • Oversized interior anti-draft collar 
  • Ergonomic foot-box construction provides more loft and warmth 
  • Low-profile cordlock lets you un-cinch the hood with one hand
  • Insulated tube along upper hood opening seals out drafts when cinched 
  • Minimal zipper minimizes weight and reduces cold spots
  • 40"/102cm YKK #5 anti-snag zipper for a smooth, quick zip 
  • Zipper Garage
  • Interior fabric loops for sleeping bag liners
  • Streamlined exterior loops for hang drying or storage
  • Storage sack & stuff sack included

Bag Weight: 3lbs 7oz (Reg), 3lbs 11oz (Long)

Fill Weight: 38oz (Reg), 40oz (Long)

Compressed Bag Size: 8.5in x 9.5in (Reg), 8in x 10in (Long)

Stuff Sack Size: 9in x 20in 

Sleeping Bag Type: Mummy Bag

Shoulder Girth: 60in (Reg), 62in (Long)

Hip Girth: 54in (Reg), 56in (Long)

Footbox: 36in (Reg), 38in (Long)

Bag Size: Regualr - Fits up to 6ft (183cm), Long - Fits up to 6ft 6in (198cm)

Pad Size: Works with any pad size or style