Thermarest Hyperion Sleeping Bag 20F/-6C

Regular price $599.95 Save $-599.95
1 in stock
The feather-weight Space Cowboy is built with eraLoft synthetic insulation to endure the rigors of backpacking and cowboy camping in variable conditions. Designed with innovative Therm-a-Rest features like SynergyLink Connectors and Zoned Insulation, the bag is among the lightest and most packable in its class. The mummy-style bag compresses down to take up minimal room in your pack and comes in two outdoor-inspired colors. Whether exploring the western frontier, bike packing through the desert or wandering through the wild, the Space Cowboy has you covered. Storage sack and compression stuff sack included.
  • eraLoft Insulation: Efficient and compressible, our water-resistant synthetic fill uses hollow fibers to reduce weight without sacrificing warmth.
  • SynergyLink Connectors  Connectors: Integrate the bag with a mattress for optimal comfort and efficiency; removable for versatility.
  • Zoned Insulation: Maximizes warmth and saves weight by intentionally placing fill where you need it most. Placing 65% of the fill on top and 35% on the bottom keeps the Space Cowboy lightweight without sacrificing warmth.
  • Quilt and Blanket Loops: Customize your sleep system by layering our quilts or tech blankets for increased warmth.
  • Additional features: Snag-free zipper and cinchable hood.



  • 482g (Small)
  • 545g (Regular)
  • 595g (Long)
Ideal for Backpacking
  • Small fits to 5' 6" (168 cm) (Small)
  • Regular fits to 6' 0" (183 cm) (Regular)
  • Long fits to 6' 6" (198 cm) (Long)
Temperature 7°C
Shape Mummy
Insulation Synthetic
  • eraLoft
  • ThermaCapture
Construction Offset quilt
Face fabric 20-denier ripstop polyester
Lining/backer 20-denier polyester
Packed size 18x25cm
Shoulder girth
  • 144cm (Small)
  • 156cm (Regular)
  • 164cm (Long)
Hip girth
  • 144cm (Small)
  • 147cm (Regular)
  • 149cm (Long)
Foot girth
  • 108cm (Small)
  • 113cm (Regular)
  • 126cm (Long)
Additional feature(s)
  • Home storage sack included
  • Stuff sack included
  • Sleeping pad sleeve or straps
  • Ultralight
Made in China