The lightest, most efficient range of bags ME has ever developed. If you want reliable warmth for minimum weight, look no further.
Mountain Equipment says:
As efficient a bag as it is possible to make. Inspiring confidence even when water turns to ice, this ultralight bag will pack a punch in any high mountain environment during the late spring and summer.
|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 Extreme Light series, which includes the Firefly, Firelite & Fireflash sleeping bags, are the lightest bags Mountain Equipment have ever developed. They haven't gone in the minimalist direction and stripped the bags of any features, you get box-wall baffle construction, anatomical hood and foot-box, a neck and zip baffle and more.
With the Extreme Light series bags you get the quality and innovation of ME bags, whilst using some of the lightest materials out there.
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
|Help and advice:|
The Firefly 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 Firefly Down Sleeping Bag.
*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.