Therm-a-rest Mira? Women's Down Sleeping Bag and Women's NeoAir? XLite® Review

© Tired Heather

Late Summer and Autumn saw me heading out fully armed with two of Therm-a-rest's most recent ladies specific offerings- the NeoAir Xlite mattress and the Mira sleeping bag.

Sleeping bags are a recent foray for Therm-a-rest and both of these items are well up the Therm-a-rest hierarchy of kit for those serious about getting out there- whether that's a week long wild camping trip or a high alpine route.

Heather Swift testing the Mira Sleeping bag andWomen's NeoAir XLite


What are they?


The Mira Sleeping bag - is an ultralight, three-season goose-down filled bag suitable for temperatures down to -9C.

It has been designed specifically for women, with proportionally narrower shoulder and leg volume, wider width for the hips and shorter overall length. It has 750+ fill goose down with 'ThermaCapture' technology to improve warmth.

It has 'SynergyLink' connectors, which join the bag to the mattress. It features a foot baffle, has insulation targeted to key areas such as head, feet and the top of the bag, and it weighs 820 grams.

On a less technical front the Mira comes in a pretty, but practical, ruby and pink colour option, the polyester shell fabric is soft to touch and the bag has all the usual expected features: draft collars, two-way full-length zip with baffle, eternal zip pocket for handy storage, various hanging loops, and a toggle adjustable face opening.

The Women's NeoAir XLite - is an ultralight three-season air mattress - 6cm thick, weighing 340 grams, also with ThermaCapture technology and shape relevant to the female sex.

Heather Swift testing the Mira Sleeping bag andWomen's NeoAir XLite

There are a few things which piqued my interested from the very start.


What was this ThermaCapture found on both items?

To use Therm-a-rest's words it is a 'proprietary reflective lining'. To use my words it is a silver coating on one side of the fabric which reflects heat back into the bag/mattress to help trap your body heat...and has the bonus of adding no additional weight to the bag.

Fabric Sample showing ThermaCapture technology.


Was it really necessary to put two large loops under the sleeping bag to attach it to the mattress (the 'SynergyLink' connectors)?

The loops do look a little over the top so I felt very skeptical as to how practical they would be. How did the bag and mattress perform? After nights out on the mountain, bivvying, camping and even crashing on the occasional friend's floor I found bag and mat to be excellent.

How the connectors work!  © Heather Swift
How the connectors work!
© Heather Swift
A  'SynergyLink' connector.  © Heather Swift
A 'SynergyLink' connector.
© Heather Swift


Of priority I was able to sleep warmly and well, being totally comfortable at 0 degrees and especially finding the mattress one of the comfiest I have ever slept on.

Both items pack down well: the Xlite shrinks to the size of a Nalgene and fits in my helmet, great for packing.

Good for packing!
© H Swift

With sleeping bag and mattress weighing in jointly at 1160 grams they really are light weight - I could feel the difference from previous walk in's to routes fully loaded.

Heather inflating the Mattress

My lungs must be smaller than average as it did require more of my breaths than the 20 advertised to fully inflate the mattress. I won't quibble though- 25 breaths wasn't so hard work whatever the condition.


As Therm-a-rest have designed the items for women it felt good to have a good fit, and know you are not carrying excess amounts of sleeping bag.

"The biggest eye-opener was the 'SynergyLink' connectors: they are brilliant."

Not once did I slide off the mattress, which I must say is pretty slippery, no matter the slope of the ground. I could sit up unhindered and the loops really do what they are designed for.

Both products compare well with their competitors. The sleeping bag market is something of an open field when it comes to women's models as most brands do not offer many models: Therm-a-rest have come straight in with three options to ensure you can select the right one for you.The Mira compares very well on weight vs warmth with all its competitors, and is very reasonably priced.

At 340 grams the Xlite slots in well at the lighter-weight end of the market, and again is priced well.

Anything else you should know?


Check the sizing. I am 156cm tall and was testing the regular size for both items.

The fit was perfect for me, but various taller friends (up to 165cm) had the pleasure of trying the bag on my lounge floor and said they would debate trying the larger size. Try before you buy!



For a first foray into sleeping bags Therm-a-rest have done well, I picked up on no initial faults but will give the bag the test of time. The mat does make a fairly loud crackling noise when touched which took me aback the first time I got set up to sleep: it didn't bother me when sleeping though so was less of an annoyance than I had feared.

Lastly for the Xlite I followed manufacturers recommendation and never placed it directly on the ground. The fabric appears tough enough but I can imagine it would puncture easily enough if placed on something sharp.

"Overall though I would say that they are very warm, very light, no excess bag or mat, very comfy and looks pretty to boot."

Therm-a-rest have come up with two great women's products. What more could you ask for?

Therm-a-Rest Mira Women's 15°F/-9°C Bag with Therm-a-Rest NeoAir™ XLite® Mattress  © Therm-a-Rest
Therm-a-Rest Mira Women's 15°F/-9°C Bag with Therm-a-Rest NeoAir™ XLite® Mattress
© Therm-a-Rest
What Therm-a-Rest Say:

The Mira women’s down sleeping bag is the all-around winner for ultralight three-season backcountry adventures. Its three-season temperature rating hits the sweet spot for keeping you warm on everything from low elevation thru-hikes to high alpine traverses. A women’s-specific cut minimizes excess space and key features like our Toe-asis™ Foot Warmer, ultralight and compressible 750+ fill goose down, reflective ThermaCapture™ lining and mattress integration assure you’ll stay warmer, sleep better and go farther with less to carry.


The NeoAir XLite mattress delivers more warmth and comfort per ounce than any other three-season air mattress available. Our patent-pending technologies deliver that performance with minimal weight and less bulk than a one-liter water bottle. Cold sleepers will appreciate our Women’s version, featuring an added layer of our reflective ThemaCapture technology for added warmth. For the discerning alpinist, thru-hiker or backcountry minimalist who’s counting every ounce, there is simply no better choice to assure the kind of rest you need to get done what you’ve got planned for tomorrow.


Heather Swift in the Marmot Vapor Trail Hoody  © Jack Geldard
About Heather Swift:

Climbing and the mountains have shaped Heather's adult life. From childhood on a Derbyshire hill farm to living in Chamonix France, South America to Nepal, the outdoors have never been far away.

Things have moved on from those early years on the Peak's gritstone edges: bouldering, trad, sport climbing, everything Alpine, north faces and ski-mountaineering.

You can read more about Heather on her Website:

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