K1 - Primus Long John - Beyond Clothing USA
K1 - Primus Long John - Beyond Clothing USA
K1 - Primus Long John - Beyond Clothing USA
K1 - Primus Long John - Beyond Clothing USA
K1 - Primus Long John - Beyond Clothing USA
K1 - Primus Long John - Beyond Clothing USA

Primus K1 Long John

$55.00 $38.50

Available

Color
Black
Manatee Grey
Size
Fit: Standard
-
Size & Fit Guide
Length

This is a clearance item. All sales are final.

Availability:

Lightweight Next-to-Skin Performance

The Primus K1 Long John baselayer provides a powerful foundation for the rest of your system. A carefully balanced blend of wool and synthetic fibers ensures long-lasting durability, simple wash cycles, and fast, efficient moisture transport. Flat seams allow bulk-free layering, and a specialized fly delivers support and fuss-free access (even with gloves).

Fusion Wool

Our wool combines with synthetic fibers to create the ideal performance fusion for moisture management: wicking up and lifting out sweat, protecting against odors and wash shrinkage, increasing durability, and ensuring next-to-skin comfort. Your system’s moisture transport starts here.

Ballhalla™ Fly

The Ballhalla™ fly keeps you comfortable all day long with anatomical support and minimal bulk, and the unique design ensures easy access even while wearing gloves.

Performance Fit

Flat-seam construction ensures all-day comfort, delivering a smooth next-to-skin feel and reducing bulk when layering up.

K1 - PRIMUS

USE GUIDE

WHEN TO USE
Below 50° F as a next-to-skin baselayer.

PAIRS GREAT WITH
Active insulation and softshells.

BENEFIT OVER OTHER LAYERS
Highly breathable, fast-drying layer that can have any other layer worn over it.

Learn more about layering:

VIEW SYSTEM BUILDER

SPECS

  • Layer Level
    1
  • Body Material
    2.7 oz. piqué 78% polyester/27% wool
  • Weight (Size L)
    7.1 oz.
  • Wind Resistant
    No
  • Breathable
    Yes
  • Moisture Wicking
    Yes
  • Fast Drying
    Yes
  • Pockets
    None
  • Source
    Imported

Trade Agreements Act Compliant
Designed in Seattle. Imported.

Customer Reviews

Based on 36 reviews
92%
(33)
8%
(3)
0%
(0)
0%
(0)
0%
(0)
J
Jared Rapp
Great base layer

Used the Primus K1 Long John with a light soft shell pant and it was the perfect combination for both hiking and sitting. Really appreciate the merino blend, as well as the dimensions for the calves, thighs, and hip. Length is perfect and glad I didn’t go with the long. For reference ordered the medium regular and I usually wear a 32 waist pant with 33 inch inseam. 6’ and 180 pounds

B
Brian Perrotte
Primus K1 Long Johns are my new winter jam

Best long johns I’ve ever owned!! They keep me warm without over heating me!! Definitely worth every penny. Keep doing big things Beyond!!

D
Daniel B
New favorite long john

Nice and thin but kept me warm in windy 30 degree weather, worn under normal pants of course!

T
Tim R
The Perfect Addition

I do a lot of mtb riding and hiking and these are the perfect base layer. Wicks away moisture and doesn't ride up (or down). The think waistband is ultra comfy too.

W
William Kaye
Long Js

They’re warm and cover the important parts.

Need Help? Contact us with any size or fit questions. 206-767-0307

Primus K1 Long JohnSizing Information

Height 5' 8" - 6' 2"

Short: -2 Inches Inseam

Long: +2 Inches Inseam

SizeWaistHipInseam Regular
S30-3137-3829
M33-3440-4130
L36-3743-4431
XL39-4046-4732
2XL42-4349-5032
3XL45-4652-5332
4XL48-4955-5632
Body measurements in inches

Waist Preferred Pant Waist

Hip 7" Below Preferred Waist

Inseam Regular Crotch to floor

silhouette diagram

Fit Information

Standard True to Size | Active Layering

silhouette diagram
Product is Standard Fit, developed to accommodate up to two layers, for cross-environmental versatility

Expedition Oversized | Static Layering

silhouette diagram
Product is Expedition Fit, developed to accommodate up to four layers, for extensive use in extreme weather

Learn more about our layering systems

System Builder

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