Thermarest Hyperion™ 20F/-6C R Down Sleeping Bag

The Thermarest Hyperion™ 20F/-6C R is a premium down sleeping bag designed for ultralight backpacking and mountaineering. Engineered with 900-fill Nikwax Hydrophobic Down, it provides exceptional warmth-to-weight ratio and moisture resistance. The bag features a mummy shape with a contoured hood and draft collar to minimize heat loss, while the zipper baffle and draft tube prevent cold spots. The included compression sack reduces pack volume, making it ideal for minimalist adventures.

Advantages

Ultralight construction at just 1 lb 5 oz (595 g) for the regular size, this bag packs down small and offers reliable warmth to 20°F (-6°C). The hydrophobic down treatment ensures loft retention even in damp conditions, and the breathable Pertex® Quantum shell fabric balances weight and durability. The SynergyLink™ Connectors integrate with Thermarest sleeping pads for a secure sleep system.

Suitable for

• Ultralight backpacking and thru-hiking
• Three-season mountaineering and alpine climbing
• Bikepacking and fastpacking
• Camping in temperatures down to 20°F (-6°C)

Key specifications

• Temperature rating: 20°F / -6°C (EN 13537 tested)
• Fill: 900-fill Nikwax Hydrophobic Down (RDS certified)
• Shell: Pertex® Quantum (20D ripstop nylon)
• Lining: 20D nylon taffeta
• Weight (regular): 1 lb 5 oz / 595 g
• Pack size: 7 x 8 inches / 18 x 20 cm (compressed)
• Zipper: Full-length #5 YKK with anti-snag slider
• Includes compression sack and storage sack

Recommendations

For optimal performance, pair with a Thermarest NeoAir® sleeping pad and use the included SynergyLink™ Connectors. Store the bag loosely in the provided storage sack to maintain loft. Avoid prolonged compression to extend the life of the down fill.