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    • Redline, Iceline, Snowline

      Extreme Expedition Sleeping Bags

    Engineered for the most hostile environments on earth.

    For those wanting to survive and thrive in extreme conditions, our Extreme Expedition sleeping bags are engineered to withstand extreme cold in the most hostile environments on earth.

    • GORE® THERMIUM™ 10D outer shell is durably light, highly breathable and rain-resistant


      Regular price From £950.00
    • GORE-TEX INFINIUM 10D outer shell is durably light, highly breathable and rain-resistant


      Regular price From £800.00
    • GORE-TEX INFINIUMTM 10D outer shell is durably light, highly breathable and rain-resistant


      Regular price From £850.00

    Built Better

    Engineered to withstand extreme cold in the most hostile environments on earth.With durably rain-resistant fabrics and construction optimised to maximise and maintain warmth for extended periods these bags are built specifically for the needs of explorers and mountaineers undertaking the most committing journeys in the highest, coldest and most remote locations.

    Features | Fill

    Down is a unique and exceptional insulation. It is more compressible, longer-lasting, and offers better warmth for its weight than any other fibrous insulation, achieving this through a structure that traps maximum still air while weighing as little as possible. All of Mountain Equipment’s down is a by-product of the meat industry, sourced from geese and ducks. The down is removed from the birds at slaughter and processed to make it clean, hygienic and fluffy.

    800+ Fill Power Goose Down

    Our very best Eastern European goose down, with an actual minimum down cluster content of 90% and individually tested to ensure a minimum fill power of 800 cubic inches & DOWN CODEX® approved.


    In 2009 Mountain Equipment became one of the first outdoor brands to introduce independent auditing of our down supply chain. Quietly introduced, without fanfare or press-releases, DOWN CODEX® set out to understand an industry and supply-chain that was largely ignored and certainly little understood.

    All products contain a code that can be entered into our DOWN CODEX® website to trace the down that they contain. Not only can you identify the source of your down but the audit relating to that source and the down batch test results can also be viewed.

    Features | Fit

    The fit of a sleeping bag is crucial in optimising performance.A well-fitting sleeping bag is not only highly comfortable it also reduces dead air space and maximises thermal efficiency.

    • Expedition Fit

      A more generous fit that’s both longer and wider, these bags afford greater comfort when used for longer periods of time but also enable additional clothing to be worn or stored inside the bag more easily.

    • EXL®

      Our time-tested EXL® system, a patented technology developed to provide extra warmth and extra loft. It adds no weight but minimises dead airspace around the body, reduces drafts, and pulls fabric away from the down allowing it to loft maximally.

    Features | Fabric

    Fabric technology is advancing all the time and we continually seek out those fabrics that offer the lowest weight, maximum breathability, compressibility and comfort.


      For extreme conditions, GORE-TEX INFINIUM™ will protect against exposure to moisture thanks to its exceptionally breathable and multi-layer construction. With an incredibly light 10 denier outer face fabric and protective ePTFE membrane it weighs just 38g/m² yet will defend against snowfall, snow-melt and the effects of condensation; ensuring that down maintains its loft even in cold and damp conditions.


      Gore-Tex Infinium ™ 10D is also used to line the foot-box and hood of the sleeping bag. This protects the bag from moisture which might build up from wet socks, feet, snowmelt and spindrift. It also increases resistance to condensation from breathing out moist air, and protects the bag from boot liners if they have to be stored inside the bag.

    • Ultrasoft™ 20D

      Ultrasoft™ 20 fabric is used in many of our bags to provide a lightweight, quick drying and exceptionally breathable fabric. With superfine yarns and a densely woven structure to create a lightweight and downproof lining fabric. Weighing just 36g/m² it offers exceptional tear and seam slippage strength for its weight.

    Good Night's Sleep Guarantee

    Every Mountain Equipment sleeping bag comes with a separate ‘A Good Night’s Sleep Guaranteed’ temperature rating.

    Redline: -45°C/-49°F
    Iceline: -30°C/-22°F
    Snowline: -23°C/-9°F

    Features | Baffles

    Baffle structure is crucial to the performance of down sleeping bags. Without it, even the best quality down will not loft and insulate to its full potential. Baffles affect a sleeping bag’s durability, weight, and the migration of down inside them – they are the building blocks from which sleeping bags are made.

    Our neck baffles and entry-zip baffles are vital in reducing the ‘chimney effect’ of hot air flowing out of the sleeping bag’s openings, and are also useful in reducing the ‘bellows effect’ of the movement of a restless sleeper pumping warm air from the bag.

    • Vertical V Baffles

      V baffles offer exceptional down control and maximum heat retention by minimising thermal bridges and offering the greatest overlap of baffles. The 3-dimensional triangular structure gives excellent compression resistance, huge loft, and offers no direct paths through stripping from which heat can escape. V baffles also reduce the number of stitch-lines on the outside of a sleeping bag, resulting in greater protection from water and snow. Complex, uncompromising, and designed for the harshest conditions on earth, V baffles are the battle tank of baffle construction methods.

    • Horizontal 14:7 trapezoid baffles

      14:7 trapezoid baffles are a premium construction method for exceptional sleeping bags. They offer excellent overlap of baffles, reducing thermal bridges and the associated conductive heat loss. This means less down is required to keep you warm, especially under prolonged use. In trapezoid 14:7 baffles, side-walls form the ‘magic angle’ that maximises strength and stability to offer excellent down control and loft. Trapezoid baffles are lighter in weight than V baffles and offer excellent down control.

    • V Side Baffles

      V Side Baffles provide additional down control to the sides of a sleeping bag and are used in conjunction with our ground level side-seam construction. Their 3 dimensional structure running the whole length of the bag improves loft and plays a significant role in managing thermal resistance over a greater surface area of the bag.

    • Lode Lock™ collar closure

      Our Lode Lock™ collar closure with its low profile auto-locating closure combines all the advantages of a magnetic fastener with those of a mechanical lock. Rendering the traditional press-stud collar closure practically obsolete, its one handed quick release closure uses two captivated internal magnets to draw the locking mechanism together and ensure that once connected it cannot be accidentally opened. The result is an insulated collar that is more efficient and easier to operate. The collar’s down density is optimised so it moves with the user and contours to the body, while captive and elasticated drawcords ensure easy adjustment.

    • Gemini™ zip baffle

      Our Gemini™ baffle is found throughout almost our entire line of sleeping bags. It is a unique zip baffle system which replaces the bulky, down hungry twin draft tubes used traditionally on cold weather bags. The Gemini™ system is light, efficient, low bulk and supremely protective. It is grown on to the sidewalls of the sleeping bag: the integrated zip baffle utilises a continuous V-baffle system paired with a shaped and stiffened underside. With a greater contact area than a traditional tubular set-up, heat loss by convection is significantly reduced and radiative heat loss minimised. Tested through every step of its development, it eliminates heat loss almost entirely and at a fraction of the weight and bulk of more traditional methods.

    Features | Hood and Foot Piece

    The head loses a lot of heat and is very sensitive to changes in temperature, making good hood design crucial to the performance of any sleeping bag. A good hood will also keep the neck warm and reduce the ‘chimney effect’ of hot air escaping the body of the sleeping bag.

    Cold feet can spell the end of a comfortable night’s sleep or even the end of an expedition and we have unrivalled experience in designing innovative sleeping bag foot pieces. By controlling the down in a sleeping bag, the foot is kept warmer, and ensuring the foot piece fits perfectly around the lower body is crucial.

    • DC7 LV Hood

      7 baffles provide exceptional down control for long-lasting performing and excellent insulation. Smaller than our previous headline hoods, the DC7 LV reduces weight, has less deformation when cinched down small, and offers single handed closure and easy-run dual tether draw cords for greater ease of use in extreme conditions.

    • Trapezium 6

      A six baffle foot piece, our most advanced design, and featuring both our Bulls Eye™ Technology and offset Sharks Toe™ foot constructions. Its highly sophisticated baffle system maximises thermal efficiency for the coldest and most demanding environments, ensuring warm feet night after night.

    • Denali, Alaska. Photo by Fay Manners.

    Get some sleep, tomorrow is a big day

    Perfectly adapted, the Mountain Equipment range of synthetic and down filled sleeping bags are the choice of today’s leading alpinists and arctic explorers. Ensuring comfort, protection and reliable warmth in the most extreme of environments. 100% of our down is Down Codex® approved and comes from independently audited and traceable sources.

    Trace your down

    What is the DOWN CODEX code?

    Click here to get a demo code and trace