ISO 23537 is the common sleeping bag testing standard adopted and strictly enforced by the US since 2017 (Previously known as EN13537), so we decided to test our products according to the toughest standard in existence.
Ratings are based on a person wearing one long underwear layer and a beenie, sleeping on an insulated surface. Everyone's body and sleep comfort differ, and conditions of use (posture, clothing, sleeping pad R-value, wind, humidity, etc.) affect total insulation, so ISO ratings are intended as a guideline to help you compare products, rather than a guarantee of warmth.
Here is a brief description of the temperature ratings:
Comfort: the temperature at which a standard woman wearing the Selk'bag can expect to sleep comfortably in a relaxed position.
Limit: the temperature at which a standard man wearing the Selk'bag can expect to sleep comfortably in a relaxed position.
Extreme: the temperature at which a standard woman wearing the Selk'bag can remain for six hours without risk of hypothermia or death.
If you would like to understand it better, our partner REI has made a great video explaining it really simple and very straight forward. Check it out here
A proper fit is essential to fully enjoying all the Selk'bag has to offer. All Selk'bag models are unisex, meaning that is suitable for men and women.
The size you need will depend on the activity you'll use it for the most : to sleep, be active, both, or any other thing you may think of. To help you choose we’ve put together a Fitting Guide with comprehensive information.
In case you still unsure which size to choose, please contact us anytime and we'll be glad to help!
If you are between 5'3'' and 5'9'' this is your size. It can fit up to 5'11'' if you intend to use it while active, without booties.
Realtree models only
* Please keep in mind that our Original 6G model, due to a higher insulation loft (contains more padding insulation than the Lite 6G) makes it more snug, so we recommend to size up if you are 1'' to 3'' below the in between size range (i.e if you are getting the Original 6G and you are 5'9'' we recommend getting an XL)
A looser fit is better for more comfortable sleeping, while a tighter fit is better for mobility - but may restrict sleeping comfort if booties are left on.
We always recommend to size up if you are in between sizes or not completely sure. It's better to have a little bit more room while using your Selk'bag!