Therm-a-Rest Altair -18C Down Sleeping Bag

$759.95 $379.98

SKU: Therm-a-Rest_Altair_0F_Down_Sleeping_Bag Category:


The Altair sleeping bag is designed to provide efficient warmth down to 0F (-18C), while offering light, packable performance that makes each day in the mountains more enjoyable. Like all Therm-a-Rest sleeping bags, it integrates with your mattress to eliminate the sliding, twisting and cold spots that can interrupt sleep.

  • Sleep Securely: SynergyLink Connectors bring your sleeping bag and mattress together for uninterrupted sleep.
  • Sleep Warmer: Zoned Insulation puts fill where you need it most, for efficient warmth.
  • Move Freely: Our Efficient Comfort Fit design gives you room to move where you need it, without creating too much space to heat efficiently.
  • Carry Less: Lightweight, 750+ fill goose down offers compressible warmth.

Altair is the twelfth brightest star in the night sky, and is used in celestial navigation.


Draft Tubes & Collar, Snag Free Zipper, Stash Pocket, Sculptured Hood, Trapezoidal Footbox, Storage & Stuff Sack

Weight2 lbs 7 oz / 1120 g2 lbs 10 oz / 1200 g
Fits6 ft / 183 cm6 ft 6 in / 198 cm
Girth, Shoulder62 in / 158 cm64 in / 163 cm
Girth, Hip58 in / 147 cm60 in / 152 cm
Girth, Foot box40 in / 102 cm40 in / 102 cm
Width30 in / 76 cm30 in / 76 cm
Length75 in / 190 cm84 in / 213 cm
Packed dimension8 x 18 in / 15 Liters8 x 18 in / 15 Liters
EN Comfort-5 C / 24 F-5 C / 24 F
EN Limit-11 C / 12 F-11 C / 12 F
EN Extreme-31 C / -23 F-31 C / -23 F
Fill750+ Goose Down750+ Goose Down
Fill weight1 lb 4 oz / 580 g1 lb 7 oz / 640 g
Liner fabric30D Nylon30D Nylon
Shell fabric30D Nylon Ripstop with DWR30D Nylon Ripstop with DWR
Zipper sideLeftLeft
Country of OriginMade in ChinaMade in China

Temperature Ratings

Therm-a-Rest sleeping bags are rated to both US and European Norm (EN 13537) standards. All ratings are developed from procedures and testing conducted by independent organizations in the US and Europe. Sleeping bags and blankets without hoods are not subjected to EN testing.

  • EN Comfort: At this temperature, a standard woman can sleep comfortably in a relaxed position.
  • EN Limit: The lowest temperature at which a standard man will be able to sleep comfortably through the night. This rating is relatively close to those commonly used in North America.
  • EN Extreme: At this temperature, a standard woman can survive for at least six hours.

Additional information



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