Unisex Super Thermo Long Sleeve Shirt Base Layer

(40 customer reviews)


Extremely warm, dry and light. The ST shirt is perfect for the most severe environments and intense activities. The Polycolon® mesh provides 4 to 6 times the insulating value of solid knits while keeping moisture off the skin. The garment is used extensively by military and expedition forces where intense activity can cause sweat and moisture to put you at risk. This is a great choice for backcountry skiing, through hiking and hunting. Sizes: XS – XXXL. Color: black, navy, white.

Technical Specifications:

Material: 100% polypropylene
Weight: 130g
Material Weight: net 140 g / m2

SKU: 10200300 Category: Tag:
GTIN: 10200300
Brand: Brynje


Brynje original Super Thermo (ST) mesh is made from 100% Schoeller® Polycolon® synthetic yarn, knitted into a 3/8″ open weave mesh that provides 4 to 6 times the insulating power of any solid knit by weight. The polypropylene yarn absorbs virtually no moisture while the mesh design allows perspiration to pass through the garment in vapor form. Nothing wet against the skin!

Polypropylene also has a very high strength to weight ratio providing super light garments designed to withstand years of extreme use. Brynje Super Thermo base layers have been used extensively in expedition work and are worn by Special Forces troops across the globe. Brynje ST garments are not just ideal for high intensity, cold weather activities. Because of the thermostatic qualities of the mesh, these base layer garments are exceptional for warm weather use as well. “Making the case for synthetic mesh base layers.”

Additional information


Black, Navy, White



40 reviews for Unisex Super Thermo Long Sleeve Shirt Base Layer

Based on 40 reviews
  1. Ethan L. (verified owner)

    Love this base layer! It’s super comfortable and warm. I really do stay drier and warmer while being active.

  2. Anonymous (verified owner)

    The best winter baselayers. Will be buying several more in the near future.

  3. Anonymous (verified owner)

    Overall this is a really good and functional base layer. It performs as expected. The reason I give it 3 stars is the odor retention. After a few days the odor builds up. I bought it for use on multi week thru hikes and it would smell too much for that. If you only use it for a day or two then wash it, you should be ok. I will probably buy the merino wool version since I overall like the top. As an aside my merino wool tops do not smell no matter how much I sweat, so it’s not me!

  4. Anonymous (verified owner)

    Light, comfortable, and dry.

  5. Reinhard Klein (verified owner)

    I am drier and more comfortable using the mesh shirt with another layer over it than I was previously with just solid layers. I am going to shorten the sleeves by sewing back the cuffs to make them more comfortable. Great product!

  6. Adam S. (verified owner)

    I can wear it for multiple days while being active and it never smells. I’ve only washed it once because I spilled food on the cuff

  7. Anonymous (verified owner)

    Worked exactly as advertised, very happy with the product. Would buy again

  8. Fred (verified owner)

    Produit de qualité, dépassé toute mes attentes. Super efficace pour éloigner l’humidité de ma peau et me faire sentir plus au sec et au chaud. Je recommande fortement pour toutes activités de niveau élevées à intense pour bien gérer la sudation.

  9. Kurt (verified owner)

    Love it! It makes such a huge difference in terms of warmth and sweat control.

  10. Ray D. (verified owner)

    This was a gift for my hunting partner after my experience.

  11. Vernon (verified owner)

    I’m a stout 5’8”, and the large fits well. First time using a mesh base layer, and I like it on 35°-55°F hikes, so I’ve just ordered the bottoms.

  12. JOSHUA OWOC (verified owner)

    Amazing product. Super light, and very comfy to wear as well as take on and off (other fishnet/mesh products have not been as kind). I’ve worn it under a thin wool t-shirt and a wool-mid layer that has a synthetic mesh as well in 20-40F degree weather when carrying a 50lb rucksack, going 4+ mph for 2 straight hours and when I’m done I’m completely dry and can stand around cooling down and not get chilly or cold. Can’t say the same for my buddy.

    The only (minor) con is the visibility of the collar; I wear a shirt over it and have to make sure that also fits tight around the neck to cover it up completely.

    6’1″ / 205lbs athletic build– XL fits me very well

    Grunt Proof’s video inspired me to buy this product.

  13. Michael M. (verified owner)

    Quick shipping and the product is top notch. I have been amazed at how warm this item has kept me when worn as my base layer (and no damp, clammy feeling at the end of the day from sweat!)

  14. Aaron G. (verified owner)

    I’m 6’2″ (188cm) and 210lbs (95kg) and I like the fit of the XL. Snug but not too tight or constricting. Temperatures around here rarely go below freezing but this keeps me quite warm at 40F/4C even when the shirt I’m wearing on top is soaked in sweat.

  15. paul w. (verified owner)

    Quick delivery, thanks. Haven’t had time yet to test it on a backpacking trip.

  16. Tod H. (verified owner)

    Great ventilation with shell unzipped, great warmth/weight zipped up.
    Would be even better with double layer on shoulders only, where gravity presses shell down into skin and is the first place precip leaks through

  17. Michael (verified owner)

    I’m a convert to fishnet style base layers. I’m not going back. This does what is supposed to. Warm. Doesn’t hold moisture. Air dryers quickly without odor.

  18. Montaz Meah II (verified owner)

    My girlfriend and I were super warm wearing these in Montreal at -6C/21F. She kept saying how happy she was that I bought these. Some of the days, we were so hot, we had to remove our coats. Amazing product.

  19. Austin (verified owner)

    Excellent base layer. Kept me warm while hiking a trail and just generally while out and about. Heard of your product from a YouTube channel called “Grunt Proof”.

  20. John H. (verified owner)

    great mountain fall-winter-spring layer

  21. Ronald Crandall (verified owner)

    Great base layer, comfortable and light.

  22. Andrew (verified owner)

    Fits close to the body but is otherwise a fantastic piece of kit. It’s unreal how clothing with holes in it can be this warm. Thank you Brynje!

  23. Stephen Harvey (verified owner)

    Great quality product that really works as stated
    I will purchase again from this company
    I recommend

  24. Daniel Richardson (verified owner)

    no issues with the product- tag is easily removed and the shirt is not abrasive

  25. James B. (verified owner)

    This is the best base layer money can buy. Moisture transfer and warmth to weight are better than any other undergarment I have tried. I can’t believe this garment technology has been around for so long and most Americans don’t know about it!

  26. Andrew (verified owner)

    Awesome base layer. My only complaint is that the collar is quite small, and tight around the neck. It’s the smallest and highest-riding collar of all the base layers I own. There isn’t any combination of shirts I can wear that doesn’t show the collar and the bright white logo on my neck, plus some of the fishnet material. Therefore I don’t wear it if I’m planning to be in public because it just doesn’t look right sticking out of your clothes for day to day business and going out to eat. With a black shirt on from a distance you might look like a priest. Up close, the mesh makes you look like you’re on your way to a stripping gig. Works awesome for winter motocross/enduro, mountain biking, cutting wood, everything outside.

  27. Bill B. (verified owner)

    As described: Dry, warm, lightweight.

    I’m not sure that it is better per gram than Alpha Direct as a base layer, but I prefer Brynje over any other thermal underwear I have worn.

  28. Christopher (verified owner)

    If I could only have one shirt it would be the ST long sleeve, the magic layer. My next one will have the shoulder inlays.

  29. Sean G. (verified owner)

    (Partly copied from my review of the wool version) Works very well. I’m a heavy sweater, regardless of layer arrangement. The mesh shirts allow me to stay warm longer when I stop moving, and my layers seem to dry out more quickly on my body. Seems durable and so far hasn’t hasn’t held onto odors. I do wish there were something other than the mesh to grab to pull the sleeves all the way onto my arms. They seem to want to bunch at the wrist. Maybe a little more room in the forearms would be helpful.

  30. Caleb Hoffman-Johnson (verified owner)

    Bought this top and wore it through 30 days of USMC training with temperatures regularly reaching double-digit negatives. Perfect base layer to wear stand-alone under a shell or under additional mid-layers if things got super cold. Kept me warm the entire time and was easy to clean. Highest recommendation for military or non-military use. 100% worth the money and a piece of gear I’ll use for hunting, skiing, and any other cold-weather activities in the future.

  31. Holt J. (verified owner)

    I bought this for my dad. He uses it every morning when he walks the dog. They live in the desert, so mornings start off very cold but rapidly warm up. The base layer is perfect since it keeps him warm when it’s cold and breathes as the temperature rises. He loves it!

  32. Samuel (verified owner)

    Incredible! Used it for six weeks of the Marine Corps’ toughest cold weather mountain training in the high Sierras and could not be more pleased with its performance. Kept me consistently warm and dry as I transitioned from sweating it out on long movements under heavy load before settling into camp for nights where the temps dropped below zero—wicking abilities are truly incredible. Didn’t take off for a week at a time and it kept working with minimal smell. Customer service also unparalleled.

  33. Jens Aarnaes (verified owner)

    I am a ski instructor in Colorado and this layer is by far the warmest and most comfortable one I have. To be most effective I find I need a solid layer directly on top of this mesh layer and when layered this way I am warm on even the coldest days.

  34. Peter Scott

    I recently returned from a seven day 1,180 mile journey around Ring Road in Iceland. The weather varied from a misty drizzly day of 45 F and a 13 Mph wind at Grimsey Island Artic Circle to a pleasant 70 F in Egilssadir. Yet, even at 70 F, there was still an occasional cool wind. While hiking to the Arctic Circle, I wore the Super Thermo mesh short sleeve shirt under the Buffalo Special 6 jacket. That was actually too warm. But, with a temperature of 55 F at Glacier Lagoon and a slight breeze, while walking about some trails, I wore the Long Sleeve Super Thermo shirt under a Buffalo wind shirt. I also wore the thermal under the foul weather gear provided for the Zodiac glacier boat tour. I was comfortable near the cooler climate of the glacier.
    While in Iceland, 90 percent of the time I wore only a thermal shirt and the wind shirt for comfort. In addition, throughout my trip, I also wore the Super Thermo Lined beanie. I was very happy with the comfort of these light easily packable products provided me during my exploration of Iceland.

  35. Jennifer Boyts (verified owner)

    This shirt absolutely exceeded my expectations! What a fantastic piece of gear! It is very soft and comfortable against your skin and very warm. I wore it for about 7 nights as a sleep shirt as I sleep very cold and it kept me very warm. Wore it around camp as well and it was equally impressive! I’m probably going to buy one in navy with the inlay for wearing with a pack. Excellent product, you won’t be disappointed.

  36. Scott

    I agree with Joseph. The neck logo doesn’t serve the shirt well. Other than that, great shirt.

  37. Rick (verified owner)

    Forgot! Great customer service from Jeff. Went way out of his way to get my back order to me. Much appreciated!

  38. Rick (verified owner)

    These work great! Much more comfortable on my winter bike rides. Quality construction and true to size.

  39. Joseph McCormick (verified owner)

    Great except for logo on neck

  40. Sarah Stabley (verified owner)

    I’m 5’3’ and 160 lbs female. I ordered a medium and it fit perfectly.
    I slept in these at 28* with a 10* down quilt and was snug as a bug.
    At 4.6oz for a medium I would highly recommend these for those wanting to cut oz and still be warm!

Add a review

Brynje Size Chart

Unisex Shirt Sizing Height Waist Chest
XXS 4ft 9″ – 5ft 25″ – 27″ 32″ – 34″
XS 5ft 1″ – 5ft 3″ 27″ – 29″ 34″ – 39″
SM 5ft 4″ – 5ft 6″ 29″ – 31″ 37″ – 40″
MD 5ft 7″ – 5ft 9″ 32″ – 34″ 40″ – 42″
LG 5ft 10″ – 6ft 35″ – 38″ 42″ – 44″
XL 6ft 1″ – 6ft 3″ 39″ – 42″ 45″ – 48″
XXL 6ft 4″ – 6ft 6″ 43″ – 45″ 48″ – 50″
3XL 6ft 7″ – 6ft 9″ 46″ – 50″ 51″ – 53″
Women’s Shirt Sizing Height Waist Chest
XS 4ft 9″ – 5ft 25″ – 27″ 28″ – 32″
SM 5ft 1″ – 5ft 3″ 27″ – 29″ 33″ – 36″
MD 5ft 4″ – 5ft 6″ 29″ – 31″ 37″ – 39″
LG 5ft 7″ – 5ft 9″ 32″ – 34″ 40″ – 42″
XL 5ft 10″ – 6ft 35″ – 37″ 42″ – 44″
XXL 6ft 1″ – 6ft 3″ 38″ – 40″ 45″ – 48″
Unisex Pants Sizing Height Waist Inseam
XXS 4ft 9″ – 5ft 25″ – 27″ 27″ – 28″
XS 5ft 1″ – 5ft 3″ 27″ – 29″ 29″ – 30″
SM 5ft 4″ – 5ft 6″ 29″ – 31″ 30″ – 31″
MD 5ft 7″ – 5ft 9″ 32″ – 34″ 31″ – 33″
LG 5ft 10″ – 6ft 35″ – 38″ 33″ – 35″
XL 6ft 1″ – 6ft 3″ 39″ – 42″ 35″ – 36″
XXL 6ft 4″ – 6ft 6″ 43″ – 45″ 36″ – 37″
3XL 6ft 7″ – 6ft 9″ 46″ – 50″ 37″ – 38″
Women’s Pants Sizing Height Waist Inseam
XS 4ft 9″ – 5ft 25″ – 27″ 27″ – 28″
SM 5ft 1″ – 5ft 3″ 27″ – 29″ 29″ – 30″
MD 5ft 4″ – 5ft 6″ 29″ – 31″ 30″ – 31″
LG 5ft 7″ – 5ft 9″ 32″ – 34″ 31″ – 33″
XL 5ft 10″ – 6ft 35″ – 37″ 33″ – 35″
XXL 6ft 1″ – 6ft 3″ 38″ – 40″ 36″ – 37″
Hat Sizing Circumference Actual Hat Size
Small/Medium 21 1/8″ – 22 1/4″ 6 3/4 – 7 1/8
Large/Extra-Large 22 5/8″ – 23 7/8″ 7 1/4 – 7 5/8
Glove/Mitten Sizing Circumference of Palm
SM 6.5″ – 7.5″
MD 8″ – 8.5″
LG 9″ – 10″


All sizes are averages and approximate. Your size may vary depending based on your body shape and the model.

Mesh base layers are generally quite stretchy in all directions and are cut long. As the girth increases the length will decrease

Generally the Women’s sizes will be one size smaller than Unisex. I.E. a Unisex SM is equivalent to a Women’s MD.

Laundry Instructions

Wool is a natural fiber which does not to be laundered regularly. A global wardrobe survey in 2015 by AC Nielsen confirmed that wool garments have a longer life than cotton – as much as 50% longer. Merino wool can be worn multiple time between washings which will prolong the garment life and protect the environment. The synthetic fibers like Schoeller® Polycolon can be machine washed and hung to dry.

Hand wash or machine wash on gentle cycle with cool water (not to exceed 85°F).

Line dry. Do not tumble dry.

Do not use bleach.

Do not use fabric softener.

Do not dry clean.

Brynje USA