• Rab Mythic Down Sleeping Bag -6C front view ultralight hooded down mummy sleeping bag
  • Rab Mythic Down Sleeping Bag -6C packed in storage bag for lightweight backpacking
  • Rab Mythic Down Sleeping Bag -6C hood close up showing face seal and draft protection
  • Rab Mythic Down Sleeping Bag -6C hooded side view on sleeping pad
  • Rab Mythic Down Sleeping Bag -6C open front view showing reflective lining
  • Rab Mythic Down Sleeping Bag -6C top view on sleeping pad with insulated hood
  • Rab Mythic Down Sleeping Bag -6C side sleeping fit demonstration on sleeping pad
  • Rab Mythic Down Sleeping Bag -6C hooded side view on sleeping pad
  • Rab Mythic Down Sleeping Bag -6C side profile on sleeping pad showing loft and warmth
  • Rab Mythic Down Sleeping Bag -6C zipper and hand warmer opening detail
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Rab

Rab Mythic Ultra Down Sleeping Bag (-6°C)

Rab Mythic Ultra Down Sleeping Bag (-6°C)

$825.00 CAD
$825.00 CAD
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Size

Rab Mythic Ultra Down Sleeping Bag (-6°C) – Elite Ultralight Performance for Cold-Weather Missions

Push your limits without carrying extra weight with the Rab Mythic Ultra Down Sleeping Bag (-6°C)—a cutting-edge sleep system built for alpinists, fastpackers, and serious backcountry adventurers. Designed to deliver exceptional warmth with minimal bulk, this bag redefines what’s possible in ultralight performance.

At its core is 900-fill power European goose down, delivering outstanding insulation while keeping pack weight impressively low. Combined with Rab’s innovative Thermo Ionic Lining Technology (TILT)—a titanium-infused reflective layer—the bag helps trap and reflect body heat, boosting thermal efficiency without adding bulk.

Why You’ll Love It

  • Extreme Warmth-to-Weight Ratio – Designed to maximize insulation while minimizing pack size
  • 900FP Premium Down Fill – Exceptional loft and heat retention for cold conditions
  • TILT Heat-Reflective Technology – Reflects body heat back toward you for added warmth
  • L.O.F.T 3D™ Baffle Construction – Prevents down migration and maintains consistent insulation
  • Ultralight Pertex® Quantum Fabric – Durable, wind-resistant, and highly packable
  • Compact Pack Size – Ideal for fast-moving missions and minimal gear setups

Built for Fast & Light Expeditions

Every detail of the Mythic Ultra is engineered to reduce weight without sacrificing performance. Its tapered mummy shape, anatomical hood, and draft collar work together to retain heat efficiently, even in cold alpine environments.

With a comfort limit of around -6°C (20°F), it’s ideal for three-season to shoulder-season use, from high-altitude trekking to lightweight alpine missions. 

Perfect For

Alpinism • Fastpacking • Ultralight Backpacking • High-Altitude Trekking • Cold-Weather Camping

Go Further, Pack Lighter

If you're chasing maximum performance with minimal weight, the Rab Mythic Ultra -6°C is one of the most advanced sleeping bags available—built to keep you warm, fast, and moving in demanding environments.

Features

Every detail of the Mythic has been designed to reduce weight and bulk, drawing on over 40 years of hard-won expertise. It’s filled with high-quality 900FP down, which offers superb warmth for its weight, in our groundbreaking L.O.F.T 3D™ construction. This unique technology uses twisted, helix-shaped baffles to create funnel points within the bag, which prevent down from migrating and keep it evenly distributed. Combined with a TILT lining that reflects heat back towards your body, this allows us to achieve an unrivalled warmth-to-weight ratio. Light on grams but not on functionality, the Mythic is finished with a Pertex® Quantum ripstop fabric to ensure it stands up to mountain environments. Ultralight, stripped-back, and uncompromisingly warm, it’s ideal for moving fast in cool conditions, from fastpacking to alpinism.

Hand-filled in the UK, all our down bags benefit from never having had their down compressed before use, preserving its loft and warmth.

Pioneering L.O.F.T 3D™ construction features helix-shaped baffles that prevent down migration and maximise warmth retention.

Built with a heat-reflective TILT lining, minimising radiant heat loss for virtually no extra weight.
Sleep comfortably on your side thanks to the sidewall baffles, which reduce cold spots and ensure you’re not lying on a seam.

Cinch in the hood to seal in the heat, while the down-filled collar sits snugly around your neck.

The tapered mummy shape is incredibly efficient on pack size.

½ length zip features an insulated zip baffle to prevent cold spots when the temperature drops.
Internal cordlocks positioned below your collar bone for greater side sleeping comfort.

Anatomically shaped foot box allows you to sleep in a relaxed position.

Lightweight dry bag compression stuff sack.

Zipped storage sack with water-resistant base for home storage.

Hand-filled in Derbyshire UK.

Specifications

Weight: 700g/1lb 8.69oz

Insulation: 900FP European goose down with Grangers fluorocarbon-free hydrophobic finish (355g / 12.5oz)

Main fabric: 10D Pertex Quantum ripstop (26g/m²) with fluorocarbon-free DWR

Fabric lining: 10D Recycled Atmos (28gsm) with Thermo Ionic Lining Technology (TILT)

ISO (23537-2:2022) temperature rating
- Comfort: 0°C (32°F)
- Limit of comfort: -6°C (21°F)
- Extreme: -24°C (-11°F)

Packed size: 18cm x 30cm (7.1in x 11.8in)

Carbon-neutral shipping on all orders
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