Mountain Equipment Helium 400 Down Sleeping Bag

-3°C Comfort Limit, 385g of 700+ Fill Power Down
Weighs 836g (Regular bag)
Code: SS18140V
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Efficiently sized, supremely comfortable and low in weight sleeping bag offering all-round performance.

Mountain Equipment says:

An incredibly light, versatile and packable sleeping bag well suited to backpacking and cycle touring that will still happily cope with cooler nights during the spring and summer months.

Mountain Equipment use their own 'Good Nights Sleep Guaranteed' rating which they believe is a more accurate number for some sleeping bags and is based not just on the EN test results but on lab testing, their own use, thermal imaging and cold chamber work, along with a lot of data analysis. The figure above is what they consider to be the lowest temperature that you will be comfortable at when using this bag.

Mountain Equipment's Helium Sleeping Bags are made using ME's Helium fabrics, hence the name, making them exceptionally light, compressible and tough. The densely woven construction ensures the highest levels of down-proofing, wind resistance and resistance to heat loss.

Duck down is not widely used in high-end sleeping bags, there's no reason why it shouldn't be as it gives really good fill powers for a better price than Goose down. With Mountain Equipment sleeping bags you can trace your down back to the farm and find out exactly the fill power used to fill the bag that you have in your hands. You can do this all through 'The Down Codex'. We tried it with one of our Helium bags from the warehouse and it showed the actual fill power was over 800. This is because ME have to quote the minimum possible down fill power that may be from that batch of down, in reality the fill power is often significantly higher than quoted. 

The Helium has lots of features that optimise the warmth for weight ratio of the bags. ME are so into their sleeping bag efficiency they even have a 'Doctor of Down' in their team, the only person in the world to have a Phd in down use in outdoor garments and equipment. With the knowledge they have in their team they have come to the conclusion that the traditional EN tests don't accurately represent the temperature ratings of their bags. So they've come up with their 'Good Night's Sleep Guarantee', which is their rating devised through testing in the field, in university cold rooms and labs as to at what temperature the bag should keep you comfortable. You will find this rating listed in the Specifications. For comparison purposes we also quote the EN test ratings.

- Reviewed by Ultralight Outdoor Gear

Read reviews here:

Help and advice: Choosing a sleeping bag advice
  EN 13537 rating for sleeping bags explained
  Sleeping bag shape and sizes advice
  Sleeping Bag features Page 1
  All about down filling in sleeping bags
  • HELIUM 20 outer shell is very light and highly breathable
  • 385g of 90-10 Pure Duck Down with a minimum fill power of 700
  • Alpine fit maximises thermal efficiency
  • Slanted Box-Wall baffles throughout
  • Mid-level side seams
  • 5 baffle anatomically shaped hood
  • 4 baffle anatomically shaped and offset foot-box
  • Full length Gemini™ zip baffle and integrated collar with Lode Lock closure
  • Supplied with waterproof roll-top stuff-sack and storage cube

The Helium 400 can be coupled with all Mountain Equipment sleeping bags with the exception of bags from the Classic, Dream & Sleepwalker ranges. Couple this bag with one with a zipper on the right hand side. Contact us if you are interested in ordering a bag that will couple with the Helium 400 Down Sleeping Bag.

There is a Right Zip version of this sleeping bag. Please contact us to find out more and for availability of these bags here.

Product FAQ:

Does the ME Helium 400 have a DWR water repellent finish on the outer (for condensation etc) and has the down been treated at all for water repellence?

The outer fabric of the Mountain Equipment Helium will have a DWR coating to help protect against condensation etc.

Mountain Equipment don't use hydrophobic treated down in their premium sleeping bags. After testing they feel that it's unnecessary as only the outer layer of down gets wet and due to the amount of fill it doesn't become a problem. The jury is still out on whether these treatments impact on the life span of the down and it's ability to loft in the long term.

Regular Long
  • Weight: 836g
  • Length: 190cm/75in
  • Width: 75cm/30in
  • Foot width: 50cm/20in
  • Weight: 864g
  • Length: 205cm/81in
  • Width: 75cm/30in
  • Foot width: 50cm/20in
  • Comfort: 3°C/37°F
  • Comfort Limit: -3°C/27°F
  • Good Nights Sleep Guaranteed*: -5°C/23°F
  • Extreme: -19°C/-2°F
  • Fill Weight: 385g / 14oz
  • Pack Size: 24cm x 20cm x 17cm

*Mountain Equipment use their own 'Good Nights Sleep Guaranteed' rating which they believe is a more accurate number for some sleeping bags and is based not just on the EN test results but on lab testing, their own use, thermal imaging and cold chamber work, along with a lot of data analysis.

Showing our 2 Mountain Equipment Helium 400 Down Sleeping Bag reviews with an average rating of Excellent. Would you like to write a review?
Review Summary - 5 out of 5 based on 2 ratings.
April 14, 2019 | Alex Ball
A solid bag.

An excellent bag: - Nice and light and compresses well for when you're on the move, I use a 38l ruck when through hiking and having this bag left plenty of space for my other gear. - You're going to be snug, I had nights that dropped to around -5 and I was fine in just the bag. My liner helped on the even colder nights but the bag held its own very well. The bag also has a little magnetic clip to help keep it zipped up and the toggles for tightening the hood hold fast as well, but are a little fiddly when trying to emerge! - Despite my tent condensing, the water didn't permeate the outer lining at all and the down remained dry and warm for 5 days, which was a god send! - The bag comes with a bog standard dry bag which is decent quality, and the (airing?) cube is also great for storage at home. The only down (excuse the pun) side is that I wouldn't recommend the regular for anyone over 6'2/3", that's my height and I was pushing it!!

Ultralight Outdoor Gear Limited
September 28, 2018 | Ben Patient
Perfect bag

Bought this on the recommendation of the great staff at Ultralight Outdoor Gear. Absolutely delighted with it. Warm, comfortable and light.

Ultralight Outdoor Gear Limited