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  • Merino wool wicks away moisture and breathes to regulate temperature for outstanding comfort in a variety of conditions
  • Air can circulate in the natural hollow spaces of the wool fiber and moisture is wicked away to keep you cool and dry
  • Merino wool naturally resists odors
  • The Cocoon Merino Wool Mummy Liner will add about 12°F (7°C) of warmth to your sleeping bag


View all Cocoon Sleeping Bag Liners

REI membership


Best Use Backpacking, Camping
Sleeping Bag Shape Mummy
Added Warmth (F) Up to 10 degrees
Added Warmth (C) Up to 7 degrees
Stuff Sack Size 3.5 x 7 inches
Material(s) Merino wool
Dimensions 86 x 32 (shoulder) x 24 ( foot) inches
Weight 17.5 ounces
Weight - Metric 0.5 kilograms
Gender Unisex
Rated 5 out of 5 by from Good for Sweaty Sleepers I got this a year and a half ago (earlier version, no drawstring) because my meds make me sweat at night and it's gross. At home, the only thing that helps is natural fibers, so wool was the only bag liner choice for backpacking. After almost 2 summers, I love it. My sweating is reduced, but even when I do sweat, I stay warm, it still has a nice skin feel, and it doesn't stink. A+ just for that. I'm a cold sleeper, so the added warmth from the additional insulation is great, and the cozy wool also just feels warmer than bare sleeping bag, and hugs my body. It's nice and stretchy, I can fold my legs in through the top opening and it keeps its shape. When it's hot, I can use it as a top sheet. If it gets sweaty, muddy, full of bug spray and sunscreen, it's easy to throw in the wash (on delicate, and no dryer). It is heavier than non-wool options. I prefer some weight on me when I sleep so that's a plus for me. I love it and use it for all my camping needs, whether backpacking or car camping, hot or cold.
Date published: 2015-08-16
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Is there a zipper? If there is, how long is it?

Asked by: buckethead
The Merino Wool Mummy Liner is zipperless. It is sewn up to the opening on both sides.
Answered by: REIservice
Date published: 2016-12-12

What are the laundering instructions?  Can moths harm it?

Asked by: mister safety
Moths can eat through wool, they love it. Wash it on cold gentle cycle and air dry it. Woolite or no detergent. 
Answered by: Jamestown89
Date published: 2016-10-28

Is this product 100% Merino Wool?

Asked by: aCSguy
Yes, the Merino Wool Mummy Liner is made from 100% Merino wool.
Answered by: REIservice
Date published: 2016-11-09

Is this a constricting liner ? 

Asked by: Onthefly
This liner is fairly spacious. Most people do not find it constricting, however, that may be a matter of personal preference as some people do not like mummy bags.
Answered by: REIservice
Date published: 2017-01-23
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