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Mythic Ultra 360 Down Sleeping Bag


With its world-first heat-reflective Thermo Ionic Lining Technology, the Mythic Ultra 360 delivers pioneering protection for those who need to make every gram count.

Weight : 606g / 21.3oz
Rab Sleep Limit : -8C / 17.6F
Pack Size : 36 x 18cm/14.2 x 7.1 inches
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With its world-first heat-reflective Thermo Ionic Lining Technology, the Mythic Ultra 360 delivers pioneering protection for those who need to make every gram count.

For mountain marathon runners and high-end alpinists who need to travel light, the Mythic Ultra 360 is a game changer. Built from ultra-lightweight 7D ripstop nylon, it uses Thermo Ionic Lining Technology (TILT) to coat the fibres with titanium, helping reflect the user’s radiant heat back into the bag without compromising the fabric’s breathability. While that reduces the amount of down required for a given level of warmth, the angles of the bag’s trapezoidal boxwall construction also improve the evenness of down distribution, eliminating cold spots.

Made in the UK with 900 fill power R.D.S. Certified European goose down, a weight of just 606g ensures the Mythic Ultra 360 provides one of the most efficient warmth-to-weight ratios in the world.

TILT - Thermo Ionic Lining Technology

TILT technology was born out of a desire to improve heat retention without adding extra weight. TILT stands for Thermo Ionic Lining Technology, it is a heat-reflective fabric treatment designed to substantially reduce radiant heat loss without any compromise to pack size or breathability. Taking our inspiration from technology used in space exploration and emergency blankets, we have created a new Titanium 7D fabric. The fibres of this fabric have been specially coated with titanium which reflects heat back towards the body and reduces radiant heat loss by up to 32% when used as a lining, or 15% when built in to the lining.



Light Ultralight

Pack Size

Moderate Pack Size Ultra Low Pack Size

Environment Use

Cold Extreme Cold

These ratings compare our products to each other. All our products, at any rating, are of the highest quality.


Fast & Light Adventures

Key Specs

  • Weight:606g / 21.3oz
  • Temperature:Comfort; -2°C ( 28°F), Limit; -8°C ( 18°F), Extreme; -27°C ( -17°F)
  • Product Code:QSI-35


  • Super lightweight 7D Ripstop Nylon Outer Fabric
  • Super lightweight 7D ripstop nylon with thermo ionic lining technology (TILT), heat reflecting to boost warmth
  • 900+FP R.D.S Certified European Goose Down
  • Rab® Flourocarbon free Hydrophobic Down developed in conjunction with Nikwax®
  • 606g / 21.3oz saving baffle construction, preventing down shift/migration
  • Trapezoidal chamber design to eliminate cold spots
  • Proportionally designed differential cut
  • Anti snag bonded zip guard
  • Ergonomically designed internal collar and hood
  • Angled foot box
  • ½ length YKK® 3 coil main zip with noctilucent puller
  • Lightweight Dry bag compression stuff sack
  • Cotton storage sack
  • Filled in Derbyshire UK
  • Left zip only
  • Temperature tested to new European standard: EN1357:2016
  • Pack Size: 36 x 18cm/14.2 x 7.1 inches
What is TILT?
Qu’est-ce que le traitement TILT ?
Was ist TILT?
The inner lining uses Thermo Ionic Lining Technology (TILT) which reduces radiative heat loss by reflecting heat back towards the body resulting in increased levels of warmth. This dramatically increases the Mythic Ultra’s warmth-to-weight ratio without changing the original fabric’s properties or increasing weight.
La doublure intérieure comprend la technologie Thermo Ionic Lining (TILT) qui réduit les pertes de chaleur radiative tout en réfléchissant la chaleur pour la renvoyer en direction du corps, ce qui permet d’offrir des niveaux de chaleur plus élevés. Cela augmente le ratio chaleur/poids du Mythic Ultra de façon spectaculaire, sans changer les propriétés de son tissu original, ni augmenter son poids.
Das Innenfutter mit Thermo-Ionen-Futtertechnologie (Thermo Ionic Lining Technology – TILT) reduziert den Strahlungswärmeverlust, indem sie die Wärmestrahlung zurück in den Schlafsack reflektiert. So wird für wohlige Wärme gesorgt. Dies optimiert das Wärme-Gewicht-Verhältnis, ohne die ursprünglichen Eigenschaften des Gewebes oder das Gewicht des Schlafsacks zu beeinträchtigen.


Rab ships throughout the UK, EU and the United States. All UK orders are shipped free of charge by DPD. Orders placed during the week and before midday will typically be delivered within 48 hours, orders placed on weekends will ship on the following Monday.

For more information regarding shipping, including shipping charges and estimated delivery times, please visit our help centre.


If you are unhappy with your purchase, please return it to us within 28 days of receipt. The item(s) must be in resalable condition with tags attached. We are currently unable to exchange items and will refund products returned to us under the policy above.

Please note, we are not able to accept returns for underwear unless the product is faulty or damaged. We advise that you use a recorded courier service to return your item(s) as we cannot be responsible for items lost in the post.

For more information regarding returns and warranty, please see our help centre.

Mythic Ultra 360 Down Sleeping Bag Reviews