Excelling in damp conditions, the Cloud Peak 400 is our warmest synthetic sleeping bag – ideal for damp winter camping and cold weather backpacks.

  • Synthetic fill keeps its insulating loft when damp
  • Durable outer fabric that can take a beating
  • Fill withstands repeated compression and washing

The Cloud Peak 400 uses 400gsm Thermolite® Ecomade fill, compressible synthetic insulation with a high warmth to weight ratio. Thermolite® keeps its insulating loft when wet which makes it ideally suited to camping in cold, wet climates. It also gives you the security of knowing your sleeping bag will still keep you warm at the end of a long backpacking trip, or after a whole winter of use.

Thermolite® is highly compressible and recovers better from being bundled into stuff sacks. This provides long-lasting loft, season after season, extending your bag’s lifespan. It has much better washing durability too, so you don’t need to worry about bunging your bag in the washing machine when it gets a bit funky.

We’ve designed the Cloud Peak range to stand up to the demands of repeated heavy use. As well as the robust Thermolite® fill, we’ve chosen a hardwearing nylon ripstop for the outer fabric. This is treated with a PFC-free water repellent for extra damp resistance and protection from catastrophic tea spills.

A slightly tapered mummy shape uses less energy to warm up and the full length zip baffle reduces heat loss. The hood and neck baffles can also be cinched right down to keep you snug and draught-free.


Key Features

  • Thermolite® insulation is highly compressible and recovers well for repeated use
  • Synthetic fill keeps its loft even when damp, ideal for multi-day trips
  • Durable outer fabric can take more of a beating for regular camping
  • Fill is designed to withstand repeated washing
  • Drawstring neck and hood baffles and a full-length zip baffle to lock in warmth
  • Baffles use a stitch-through construction, reducing fabric to save weight
  • Outer fabric is treated with a PFC-free water repellent for greater damp resistance
  • Adjustable compression bag included
  • 3 Year Alpine Bond

Vital stats

Temperature Ratings

AK Sleep Limit: -8°C/17.6°F
Our recommended usable limit of the bag. The majority of our customers will find this to be the tipping point between a comfortable and restless night’s sleep.

Tog: 10


Fill: 400gsm2 Thermolite® T3E-ML Ecomade
Outer Fabric: 40D nylon, 300T ripstop, 54gsm
Inner Fabric: 20D polyester, 45gsm
Baffles: Stitch-through construction


Internal: 200cm x 80cm (widest point)
Packed Size: 46cm x 27cm (uncompressed)


Sleeping Bag: 1728g
Stuff Sack:

Origin: China

Sustainability & Care

Product Care Information

Your sleeping bag doesn’t like to feel cooped up. Storing it uncompressed will extend its life and allow it to regain its loft quicker when you pull it out.


Recycled Materials
Thermolite® EcoMade is a polyester-based insulation using 35% recycled content, including from plastic bottles!

The Cloud Peak 400 uses a PFC-free durable water repellent treatment on its outer fabric to help shed moisture. PFCs are potentially harmful chemicals that have been found to build up in the environment.