Xero 1000 Down Sleeping Bag

Expedition bag for long high-altitude ascents and polar challenges, cut wide enough to accommodate a full set of down clothing.
Typical Operating Temperature
Guideline minimum temperature. Sleeping Bag TOT: you should get a night’s sleep, under normal circumstances. Clothing TOT: you should feel warm enough, assuming low/moderate activity. Sleep System TOT: relates to full system. For more details, see our Technical Briefing.
-38°C / -36.4°F
For clothing, weight is for size: M. For sleeping bags, weight changes with selected length/width. N.B. there may be some variation in the weights of finished products.
1860g / 66oz
Xero 1000 Down Sleeping Bag


  • Extra width for expedition use
  • Exceptional 900 fillpower European Goose Down
  • Water-resistant Ultrashell outer fabric
  • Superlight MX inner fabric
  • Box-wall construction for max loft
  • Inner water-resistant panels
  • Short zip with insulated expansion gusset (more below & in 'Technical Info' tab)
  • Pack size: 25 x 44cm†
  • Mummy hood draws up close around head
  • Wide 3D Collar seals in warmth at neck
  • Trapezoid baffle system for ideal down control
  • Special baffle section stabilises down over chest
  • Side block baffles prevent down shift
  • Extra down channels along each side ensure side insulation
  • Ultrashell inner panels at head to protect against breath soaking the down
  • Ultrashell panels at inner foot to cope with damp feet/footwear
  • Short zip with down-filled gusset for security (in the event of zip failure) and for expansion room, if needed
  • Footpiece: ovoid shape to fit naturally to feet and avoid pressure
  • Black inner for quick drying
  • Stuff sac with large mesh storage sac
  • Colour: Blue (with Gold trim).
  • Set Options:
    • Rare 950 fillpower European Goose Down (bag's weight stays the same, warmth (TOT) improves)
    • Short and long lengths*
    • Full-length zip protected by double draft tubes
    • Waterproof Dri-LX outer fabric shell (+250g)‡
    • Further customisation available via our Design Your Own Sleeping Bag service

†Please note: We make our stuff sacs big enough to allow fairly easy stuffing rather than reducing the bag to the tightest minimum.

*Please note: For all length and width options we change the amount of downfill to keep the warmth (TOT) the same.

‡Please note: The optional waterproof Dri-LX outer provides an extra seam-sealed outer shell to the bag. While a shelled sleeping bag is not designed to be used alone in heavy rain (the hood area is open to the elements) the shell does protect the bag when it is used outdoors without a tent.


Ideal for long expeditions in extremely cold conditions, this Xero Down sleeping bag has been expressly designed to accommodate down clothing, even a full down suit.

The sophisticated baffle system is designed for excellent down control, while the short zip and down-filled gusset combination makes it completely fail-safe.

It is cut wide, with an inner measurement of 164cm around at the chest (enough to accommodate even down clothing inside) expanding to 182cm with the gusset open. A full-length zip version is also available for maximum ventilation.

The optional waterproof Dri-LX outer provides an extra seam-sealed outer shell to the bag. While a shelled sleeping bag is not designed to be used alone in heavy rain (the hood area is open to the elements) the shell does protect the bag when it is used outdoors without a tent, for example in a snow-hole or under a tarp.

950 down option

This option extends the range of this bag down to -42°C. Weight stays the same.

Dri-LX (weight: 64 gsm)

At just 64gsm, Dri-LX is our lightest 2-layer breathable waterproof rip-stop nylon fabric. Its remarkably low weight not only makes for a lighter load, but also reduces pack size. Its excellent waterproofing qualities are in part due to how it can be taped at the seams to create a waterproof shell for sleeping bags and clothing.

Ultrashell (weight: 40 gsm)

One of the lightest of PHD's coated materials. This ripstop nylon provides complete wind block and good water resistance at minimal weight. Ultrashell gives an excellent upgrade to performance with very little weight penalty.

Superlight MX fabric (weight: 32 gsm)

A mini-ripstop nylon with excellent tear strength, MX is the pick of the superfine 15 denier downproof materials. We have tested lighter fabrics, but most have had significant drawbacks, while our confidence in MX is based on several years of extensive use in both our ultralight and our high mountain gear.


The default zip on Xero bags is a short zip with a gusset. This is a fail-safe design. The short zip is backed by a down-filled gusset, so that when the zip is opened, the bag expands instead of opening right up. Not good for ventilation, but extra security in extreme situations in case of zip failure:

A full-length zip protected by double draft tubes is available as an option. Full zip bags ventilate well, so they can be used over a wider range of temperatures:

Our full briefing on sleeping bag zips.

950 fillpower down

A newcomer to our range. European goose of rare quality. A high value alternative at the top levels of performance. More on our down insulation.

900 Fillpower Down

European goose down of very high quality. A truly excellent down with large clusters, consistent quality and lively long-term performance. More on our down insulation.


PHD's trapezoid baffle system is used throughout. This is the best of the technical baffle systems, combining excellent down control with low baffle weight. In cross section the baffle system looks like this:

The design has a close-fitting down-filled mummy hood, and side V-channels which ensure all areas of the body are insulated. The baffles over the chest are vertically aligned, which stops any horizontal shifting of the down caused by arm movement during the night.

More on sleeping bag construction.

Proofed inner panels

Proofed fabric (Drishell or Ultrashell) panels are included inside the hood and foot areas of the bag to help keep the down dry. In very cold temperatures your breath can cause ice to form around the face opening, which may soak into the down as it melts. The panels at the foot end are to protect the down if you get into your bag with wet socks (or in extreme situations with your boots on).

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