Cuillin Bivvy Sleeping Bag

An all-in-one bivvy sleeping bag. Down-filled lower-half. Primaloft-filled upper-half. Mates with your insulated jacket. All wrapped up with a waterproof outer shell.

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.
3°C / 37.4°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.
700g / 25oz
£577.00 £462.00
Cuillin Bivvy Sleeping Bag


  • 20% off standard pricing
  • Only available until 6 July 2021
  • A half down-filled & half synthetic-filled bivvy sleeping bag in a waterproof shell
  • Fully taped waterproof Dri-LX outer fabric shell
  • Superlight MX inner fabric
  • Insulation:
    • Lower Body section - 950 fillpower down
    • Upper Body section - 60g Primaloft Gold
  • Elasticated adjustable inner waist cord
  • Hood draws up close around head
  • Stuff sac
  • Packed size: 13cm x 21cm
  • Options:
    • Lengths: Short, Standard, Long*
    • Widths: Slim, Standard, Wide
    • Colours: Red, Black, Green, White

† 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.


The Cuillin Bivvy sleeping bag is a substitute for the conventional bivvy bag and sleeping bag set-up and, like a halfbag (pied d'elephant), is designed to marry with the insulated jacket you already have. This all-in-one bivvy/sleeping bag is lighter and smaller in pack-size than a conventional sleeping bag and bivvy bag combination. The lower-half is down-filled and cinchable at the waist with an elasticated cord and works just like a halfbag to insulate your lower body. The upper-half is insulated with Primaloft Gold (60g) to mate with your lightweight insulated jacket. The whole outer is a seam-sealed waterproof Dri-LX shell. Its small pack size and light weight suit a climber’s compact rucksack and it can be used just about anywhere.

Whether it’s for the classic 2-day traverse of the Skye Ridge, simply staying high up on rocky mountains, or even a bike-packing trip with a limited payload, the Cuillin Bivvy sleeping bag allows you to overnight wherever you want.

The perfect mate for the Cuillin Bivvy sleeping bag is a down-filled jacket like the Minimus or Ultra or a synthetic-filled jacket like the Sigma or Epsilon Belay. Lightweight jackets you’d naturally take for the day. The full Sleep System gives a typical operating temperature of 3 degrees centigrade (an appropriate jacket and ground insulation is assumed). 

When the hood is cinched right down, you are left with just a small breath-hole. Of course, when it rains hard, water can get in, so get tucked away under an overhang or beneath a big boulder with a slot under it: the classic bivouac spot to keep you out of the wind and rain. A tarp stretched over the hood will do the same.

20% off standard pricing.

Only available until 6 July 2021.

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.

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.

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.

Primaloft Gold®

Primaloft Gold® is the ideal microfibre insulation. Ultrafine fibres produce an insulating core that is incredibly soft, lightweight and water resistant. In our experience it absorbs water much more slowly than other waddings, a marked advantage in wet-cold conditions.

The nearest of the synthetics to the feel of down, yet tougher than you would expect. Primaloft Gold® offers the best warmth/weight performance in the Primaloft range

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