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  • Soft fabric blend of polyester and spandex breathes well, moves moisture away from skin and dries quickly
  • Fabric also offers 4-way stretch; flatseam construction prevents chafing
  • Elastic waistband feels soft and fits comfortably
  • The men's REI Briefs have a classic fit and a functional fly

Made in USA.

View all REI Co-op Men's Briefs

REI membership


Best Use Hiking, Multisport
Fabric 92% polyester/8% spandex
Moisture Wicking Yes
Quick Drying Yes
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 3 out of 5 by from Just okay I wore Patagonia briefs for years and they developed such a stink after an hour or so of wear that I couldn't wait to take them off when done with activity. I bought a pair of Ex Officios and really like them; only nitpick is I'd like them to be a bit thinner for better ventilation. I also bought these for comparison. The REI briefs are thinner and lighter than the Ex Officios, but don't fit as well. They tend to gather a bit between my legs, not so much that I won't wear them, but the Ex Officios are more comfortable. I'll buy the Ex Officios again, but not the REI.
Date published: 2014-10-02
Rated 5 out of 5 by from These underwear are life changing. I recently moved to Austin, Texas, where summers are brutal. The cotton underwear had to go, so I started looking around for synthetics. I stumbled across a good deal on these in a fall color a few months ago while browsing at REI, and I ended up purchasing 10 pairs after I tried a pair. Game changer. I'm 5'10", 165 lbs, and I generally wear Levi's 511's, a relatively snug jean. These are super comfortable. It's virtually unnoticeable that you're wearing anything. No shift, chafe, or undue smugness anywhere, and perfect moisture wicking. Contrary to some of the reviews I've read, I've been unable to spot a downside to this underwear. They're all I've worn for 2 months, and they've held up fantastic under use and washings. Each pair still looks brand new.
Date published: 2015-07-29
Rated 5 out of 5 by from Lightweight, quick-drying brief Do you think briefs are just for men? I am an athletic woman, and I do not like bikini underwear that doesn't cover anything. These REI men's briefs are of lighter weight fabric than those made about ten years ago, but the newer fabric is soft, slinky, and dries quickly. The brief would be ideal on a backpacking trip to wash and dry en route. Blue "puget sound" color is attractive.
Date published: 2016-10-21
Rated 5 out of 5 by from When Comfort Counts I bought this for its wicking properties and comfort. It's ideal for all kinds of activities, and is a real performer in hot weather. As far as tech briefs goes, I could not be more pleased.
Date published: 2014-06-10
Rated 5 out of 5 by from unmatched breathable support Bought these for support when hiking and trail running. They offer the perfect mix of support and breath ability and are great for everyday use. Soft quality fabric and a great look.
Date published: 2014-09-15
Rated 3 out of 5 by from They're solidly OK. Overall these seem to be fine, and breathable, but the material is not as stretchy as the previous generation of REI underwear. So the fit seems to be tighter than the previous briefs. Leg holes don't seem to bind, which is usually a problem with briefs.
Date published: 2015-01-27
Rated 4 out of 5 by from Generally good product I bought these for boating because of their quick drying ability, and they do that great. The sizing works for me (large for 36 inch waist). They are, though, a bit loose in the front so if you want/need a tighter fit you might consider something different.
Date published: 2014-08-08
Rated 5 out of 5 by from soft and comfortable Bought these briefs and found them to be great for everyday use. Light and soft easy to wear.
Date published: 2014-04-18
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Are these full-rise briefs?

Asked by: nick
​No, this brief has a mid-rise design.
Answered by: REIservice
Date published: 2017-03-14

Is there are info available on the dyes used in these briefs? I'm looking for eco- and health-friendly dyes around my junk!

Asked by: theJam
​Unfortunately, that information is not available.
Answered by: REIservice
Date published: 2017-03-23
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