Extreme Alpine Sleeping Bags

Designed for alpinism's leading edge

Kryos | Xeros

True expedition bags in all but weight, redefining what is possible for those in need of high levels of protection and reliable warmth. Developed specifically for climbers and mountaineers tackling the world’s last great problems and pushing the envelope of possibility to its limit, these lightweight, protective bags are anything but simple. Providing absolute confidence for self-supported trips in remote locations, these are designed for alpinism’s leading edge.



Built better.

Built for alpinism at higher elevations, our Extreme Alpine series are expedition bags in all but weight. Now with a more adaptable yet technical Alpine 2.0 fit and revised EXL® system they are lighter and more protective than before.


These bags have been re-developed with marginal gains in mind, specifically for climbers and mountaineers faced with the prospect of climbing over thousands of metres of technical terrain. Highly efficient, exceptionally warm and protective, these are bags designed for Alpinism's leading edge.


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.

Alpine Fit 2.0

Slightly more tapered in the upper body and in the legs than our Mountain Fit this fit maximises thermal performance and minimises weight.


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.


Drilite® Loft 10D outer

Exceeding the impressive 1500 mm hydrostatic head of the original DRILITE® LOFT™ but with a staggering weight of only 28g/m2, DRILITE® LOFT™ 10D is a class-leading fabric for the most serious users: it’s amongst the lightest highly water-resistant shell fabrics in the world. Ideal for Super Alpine climbing and the most lightweight expeditions where protection, pack size and weight are critical to success and even survival.

Ultrasoft™ 10D

Ultrasoft™ 10D 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.


Drilite® Loft 10D inner

DRILITE® LOFT™ 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 or feet or from snowmelt from jacket hoods. It also increases resistance to condensation from breathing out moist air, and protects the bag from boots if, in extremis, they have to be stored inside the bag.

Good Night's Sleep Guarantee

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







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.

Horizontal 14:17 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.

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.


Discover the Range

Kryos | Xeros

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

Designed for alpine winter mountaineering and remote backcountry ski expeditions, this is one of the most reliably warm yet light and packable bags available.


Weight: 1150g / 40.6 oz

Good Night's Sleep Guaranteed: -20°C/-4°F


Expedition fit with EXL® system is both roomier and has improved loft and thermal efficiency

An ultra-light winter bag with a water resistant shell that's purpose built for those pushing the envelope of super-alpine climbing on hard, multi-day routes.


Weight: 1010g / 35.6 oz

Good Night's Sleep Guaranteed: -14°C/7°F

Explore our Sleeping Bag Range

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.


Discover the range

Extreme Expedition

Extreme Light