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Details

  • Ultra-fine 200g merino wool offers a soft feel without the scratchiness
  • Merino wool naturally wicks away sweat and resists odors
  • Low-bulk flat seams help prevent chafing
  • Crotch gusset allows full range of movement
  • Wide elastic waistband has a low profile so it's comfortable under other layers
  • Designed to hug the body for optimum performance

Imported.

View all REI Co-op Men's Long Underwear Bottoms

REI membership

Specs

Best Use Multisport
Fabric Merino wool
Moisture Wicking Yes
Quick Drying Yes
Underwear Weight Midweight
Gender Men's

Size chart

Sizing notes

SHORT: Some pants are available in short sizes, which generally means an inseam that is 2.5 inches shorter than regular sizes. TALL: Some pants, shirts, jackets and parkas are available in tall sizes, which generally means an inseam that is 3 inches longer and a rise that is 1 inch longer, a shirt or jacket body that is 2 inches longer, a parka body that is 2.5 inches longer and sleeves that are 2.5 inches longer than regular sizes.

Rated 4 out of 5 by from Low Itch Merino I've have two other brands of Merino Wool underwear. This REI version is the lowest itch of all three. If 100% Merino wool is a requirement and you are sensitive to wool this has the lowest itch factor. They have also done a good job with internal seaming, very smooth and non-irritating where the skin comes in contact with the seams. I haven't used these enough to determine how well they wear in long term use.
Date published: 2016-11-21
Rated 4 out of 5 by from Comfortable and warm Comfortable and warm I bought these long underwear while on vacation and got some on expected very cold weather these did the trick also was the first time I was in an REI store was very impressed with the store and The knowledgeable employees
Date published: 2017-03-14
Rated 4 out of 5 by from Antarctica trip Bought product for trip to Antarctica to include Kayaking.
Date published: 2017-01-12
Rated 5 out of 5 by from Great base layer. They fit very well. Been using these in this year's cold with great results.
Date published: 2017-01-21
  • y_2017, m_7, d_19, h_1
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  • REVIEWS, PRODUCT

Does it have plenty of knee flexibility to be used as a base layer for winter bicycling?

Asked by: richgfcst
The fabric has some stretch so they can be used as a base layer for winter cycling.
Answered by: REIservice
Date published: 2016-12-13

What is the average weight of this garment? I am aware that the gram weight is 200 g/m^2

Asked by: Avocado Cuddler
​The Merino Midweight Base Layer Bottoms weigh 6.8 ounces.
Answered by: REIservice
Date published: 2016-11-12

Is this item also machine washable like the top?

Asked by: George III
​​Yes it can be machine washed and dried, though we recommend air drying to increase the life of the garment.
Answered by: REIservice
Date published: 2017-01-23

Do these long underwear bottoms have a fly?

Asked by: Ike
These bottoms do have a fly.
Answered by: REIservice
Date published: 2017-01-17
  • y_2017, m_7, d_18, h_23CST
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Back to top

Please select a color/size.

Size chart

Sizing notes

SHORT: Some pants are available in short sizes, which generally means an inseam that is 2.5 inches shorter than regular sizes. TALL: Some pants, shirts, jackets and parkas are available in tall sizes, which generally means an inseam that is 3 inches longer and a rise that is 1 inch longer, a shirt or jacket body that is 2 inches longer, a parka body that is 2.5 inches longer and sleeves that are 2.5 inches longer than regular sizes.

Reviews

Rated 4 out of 5 by from Low Itch Merino I've have two other brands of Merino Wool underwear. This REI version is the lowest itch of all three. If 100% Merino wool is a requirement and you are sensitive to wool this has the lowest itch factor. They have also done a good job with internal seaming, very smooth and non-irritating where the skin comes in contact with the seams. I haven't used these enough to determine how well they wear in long term use.
Date published: 2016-11-21
Rated 4 out of 5 by from Comfortable and warm Comfortable and warm I bought these long underwear while on vacation and got some on expected very cold weather these did the trick also was the first time I was in an REI store was very impressed with the store and The knowledgeable employees
Date published: 2017-03-14
Rated 4 out of 5 by from Antarctica trip Bought product for trip to Antarctica to include Kayaking.
Date published: 2017-01-12
Rated 5 out of 5 by from Great base layer. They fit very well. Been using these in this year's cold with great results.
Date published: 2017-01-21
  • y_2017, m_7, d_19, h_1
  • bvseo_bulk, prod_bvrr, vn_bulk_1.0.0-hotfix-1
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_4
  • loc_en_US, sid_101404, prod, sort_[SortEntry(order=RELEVANCE, direction=DESCENDING)]
  • clientName_rei-inc
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getReviews, 22ms
  • REVIEWS, PRODUCT

Questions & Answers

Does it have plenty of knee flexibility to be used as a base layer for winter bicycling?

Asked by: richgfcst
The fabric has some stretch so they can be used as a base layer for winter cycling.
Answered by: REIservice
Date published: 2016-12-13

What is the average weight of this garment? I am aware that the gram weight is 200 g/m^2

Asked by: Avocado Cuddler
​The Merino Midweight Base Layer Bottoms weigh 6.8 ounces.
Answered by: REIservice
Date published: 2016-11-12

Is this item also machine washable like the top?

Asked by: George III
​​Yes it can be machine washed and dried, though we recommend air drying to increase the life of the garment.
Answered by: REIservice
Date published: 2017-01-23

Do these long underwear bottoms have a fly?

Asked by: Ike
These bottoms do have a fly.
Answered by: REIservice
Date published: 2017-01-17
  • y_2017, m_7, d_18, h_23CST
  • bvseo_bulk, prod_bvqa, vn_bulk_1.0.0-hotfix-1
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_4
  • loc_en_US, sid_101404, prod, sort_[SortEntry(order=NUM_ANSWERS, direction=DESCENDING)]
  • clientName_rei-inc
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getContent, 12ms
  • QUESTIONS, PRODUCT