Arctic Longs Base Layer with Fly

(1 customer review)


Men’s longs with fly with Polycolon® ST mesh inside a Merino wool outer layer. The combined layers provide the warmest, driest base garment in an award-winning single garment design. This is the perfect choice for hunting, snow machine riding and expedition work. Sizes: XS – XXL. Color: navy.

Technical specifications:

100% synthetic mesh lining
Exterior of 80% Merino wool and 20% polyamide
Weight: 330g
Material Weight: Shell 220 g / m2
Material Weight: net 140 g / m2

SKU: 10400402 Category:


The Arctic Double Collection is the epitome of performance under garments. Internationally recognized as the best performing base layer with numerous awards and accolades. The concept is simple, combine Brynje’s performance ST Polycolon® synthetic mesh underneath the highest quality Merino wool fabric. The mesh provides 4 to 6 times the insulating power of solid knit fabrics while allowing perspiration to “transport” in vapor form to the outer layer. The Merino wool outer layer traps the air inside the mesh cells to provide warmth while absorbing and wicking moisture away from the body. No other single undergarment provides this functionality. The Arctic Collection garments are used extensively by Police, Fire Service, Special Forces and polar expeditions. They are the best choice for extended exposure to cold temperatures and high exertion.

Additional information




XS, S, M, L, XL, XXL

1 review for Arctic Longs Base Layer with Fly

  1. M. Baker (verified owner)

    These became my go-to long underwear during the winter of 2020 – 2021. Especially for spending a lot more time seated (sedentary) working from (our rather cold) home, when I don’t generate much body heat, and also for being very comfortable outdoors in the cold. They are close fitting, a stretchy, and very warm — MUCH warmer than the usual Brynje mesh long underwear, and also my merino wool ones from other companies. The only ones that are roughly comparable are the maximally thick polyester fleece type, but they don’t fit as well, and are much bulkier under the outer regular pants. The only catch is the high price. But I like them well enough that I bought more than one, so I can wear them every day.

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Brynje Size Chart

Brynje Size Chart

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