Rab Sleeping Bag Guide

May 08, 2024

Mythic Ultra 120 Modular

Designed as the perfect complement to the new Ultrasphere 4.5 sleep mat, yet versatile enough to be used with other inflatable mats, the award-winning Mythic Ultra 120 Modular cuts weight and bulk by only including insulation where it’s not already provided by your mat. The upper bag, and underside of the legs, is filled with ultra-high-lofting 900FP down and heat-reflective TILT, reducing radiant heat loss without a gram of unnecessary weight. Meanwhile, the lower bag hooks around the mat which insulates you from the ground.


The result is an ultralight bag that, when combined with the Ultrasphere 4.5, forms a sleep system that weighs under 700g yet allows you to sleep comfortably down to 0°C. With a tiny pack size and uncompromised comfort, it’s the perfect sleeping bag for long-distance trekking, bikepacking, and multi-day mountain runs.


Mythic Ultra

Built from lightweight recycled 10D Atmos™, it uses Thermo Ionic Lining Technology (TILT) to coat the fibres with titanium, helping reflect radiant heat back towards your body 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.



The Mythic range is all about slashing weight wherever possible. The Mythic is an extremely lightweight at home in high mountains, it’s ideal for venturing out long Alpine routes, multi-day climbs, treks, or bikepacking adventures.


The chevron style baffle design keeps the down in position, optimising core warmth and reducing the amount of fabric needed compared to traditional horizontal baffles. The outer is made from our own wind- and water-resistant, recycled 10D Atmos™ fabric. The bag has a narrow mummy shape to minimise bulk, lightweight zips and pullers, and comes with a lightweight, waterproof, roll-top compression sack for protection from the elements and a small pack size while on the move.


Solar Eco

High performance, lower impact. The Solar Eco bags are built with recycled fabrics and recycled Stratus™ insulation. Ideal for the mountain bothy goer, the globetrotting backpacker, and the desert bivi in spring conditions, with a wide mummy shape for a comfortable night's sleep. 

We’ve taken everything we know about lower impact design and applied it to what we do best. These resilient synthetic bags are filled with 100% recycled Stratus™ insulation, and lined and covered with a tough, 20D, recycled Atmos™ fabric with ripstop. Hardwearing, warm, and dependable, they are fast drying and cope with condensation or damp conditions.

The Solar Eco bags have a bit more space than their higher performing Solar Ultra cousins.



Eliminating excess bulk with a highly tapered design and offering high warmth for its weight, this bag is built for fast and light mountain missions in the spring and summer. Filled with goose down and covered with a recycled, wind resistant Pertex® Quantum outer.

Intelligently baffled and a Tapered Mummy shape for an excellent warmth to weight ratio. An excellent all-round bag for trekking or fast & light in the depth of winter.



Our Alpine range is built for the mountains, whether you’re high in the Alps or deep in the Himalaya, on foot or two wheels. Offering a good warmth to weight ratio and a low bulk design, the Alpine is perfect for mountain adventures at altitude. It is filled with duck down and covered with a wind resistant Pertex® Quantum outer with a recycled nylon lining.

Engineered to maximise down performance, the Alpine bag has clever construction. Trapezoid boxwall baffles allows the down to fully loft, eliminating cold spots, and maximising warmth. The chevron baffle design improves down stability, distributing the down evenly around the whole body. In addition, the openings on the Alpine bag have been designed to reduce heat loss, with a 3D-shaped, down collar that can be cinched in snugly to trap the heat, and a down-filled baffle along the zip to prevent heat from escaping.


Neutrino Pro

The Neutrino Pro embodies the Alpine spirit. Perfect for four season adventures, its high warmth for weight makes it ideal for winter alpinism. Designed with a narrow mummy fit, for reduced bulk and pack size, and constructed with lightweight, high performance materials.

The Neutrino Pro is filled with goose down, stabilised in chevron shaped baffles, cleverly designed to reduce the amount of fabric needed compared to traditional horizontal baffles. The trapezoid boxwall baffle construction allows the down to fully loft, eliminates cold spots, and maximises warmth. Additional baffles along the length of the zip and around the neck decrease heat loss and with an adjustable drawcord around the hood you can cinch the bag around your face.

The Pertex® Quantum Pro outer is made of recycled nylon and offers wind and weather resistance, ideal for coping with condensation and damp conditions in snow holes or exposed bivi ledges.



The Ascent is built with a lightweight and durable, recycled Pertex® Quantum outer fabric and recycled nylon lining. It has trapezoid shaped, boxwall baffles that stack neatly together, encouraging the hydrophobic duck down inside to loft fully and reducing the appearance of cold spots. Hand-filled in the UK, all our down bags benefit from never having had their down compressed before use, maintaining the down’s loft and warmth.

The generous mummy fit with wide foot box provide a spacious feel for an easy night’s sleep, and the close-fitting neck baffle keeps the heat in when the temperature drops. It has a ¾ length main zip with a down filled baffle to keep out the draught.


Solar Ultra

Jam-packed with tech and built with recycled materials, the Solar Ultra embodies our drive to create more sustainable gear at the pinnacle of performance. Fast drying, lightweight and robust with heat reflecting TILT technology, the Solar Ultra offers excellent warmth for its weight. Its narrow, tapered mummy shape further reduces bulk and weight, ideal for fast and light adventures in cold, winter conditions.

Featuring a triple layer of 100% recycled Stratus™ Eco insulation arranged in a concertina shape, the Solar Ultra mimics the performance of down in a lightweight, featherless package. Reducing radiant heat loss by up to 15%, our built-in TILT technology substantially improves thermal insulation without compromising pack size, breathability, or weight. The elastic internal quilting brings the lining and insulation closer to the user, helping to reduce pockets of cold air. The localised quilting simply means that the stitching which holds the insulation in place has been minimised to reduce the chance of cold spots.


Andes Infinium

High altitude and winter expedition sleeping bag with TILT technology for warmth in extreme conditions. Offering refuge to those exploring the world’s highest peaks and the polar regions, the Andes Infinium is packed with cutting edge tech, built to keep you warm.

The Andes Infinium is filled withultra-high lofting 800FP, goose down. It is constructed using trapezoid shaped boxwall baffles, which stack together reducing cold spots and maximise the lofting and efficiency of the down inside. Reflecting heat towards the body, our TILT technology is seen as a silver sheen on this inside of the bag. Reducing heat loss by up to 32%, TILT substantially improves thermal insulation without compromising pack size, breathability, or weight.

Sleeping bags are where it all began for Rab, and they remain a core part of our range to this day. From ultralight sleeping bags designed for hut-to-hut trekking, to high fill power Down Bags for arctic sleeping with a limit rating of -40°C (-40°F), our collection strategically balances warmth, weight, and pack size for a range of activities.

Choose from Synthetic Insulation, which offers durability and resilience in damp conditions, or Down, which delivers unbeatable warmth for weight, perfect for fast and light adventures or expedition use.