Lightweight Next-to-Skin Performance
Build your day on a solid foundation with the Primus K1 Pullover baselayer. Wool balanced with synthetic fibers delivers long-lasting durability, easy wash cycles, and the fast moisture transport your layering system needs. Flat seams ensure bulk-free layering, and thumbhole cuffs combine with a ½-zip front to offer adjustable warmth.
Beyond 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.

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

Tunable Toastiness
Thumbhole cuffs extend coverage for warmer hands, and a 1/2 zip front helps shed extra heat in a hurry.

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 BUILDERSPECS
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Layer Level1
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Body Material2.7 oz. piqué 78% polyester/27% wool
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Weight (Size L)8.5 oz.
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Wind ResistantNo
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BreathableYes
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Moisture WickingYes
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Fast DryingYes
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PocketsNone
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CuffThumbhole cuffs
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SourceImported

Trade Agreements Act Compliant
Designed in Seattle. Imported.
Need Help? Contact us with any size or fit questions. 206-767-0307
Primus K1 PulloverSizing Information
Height 5' 8" - 6' 2"
Short: -2 Inches in Sleeve and Torso
Long: +2 Inches in Sleeve and Torso
Size | Chest | Sleeve |
---|---|---|
s | 36-37 | 33 |
m | 39-40 | 34 |
l | 42-43 | 35 |
xl | 45-46 | 36 |
2xl | 48-49 | 37 |
3xl | 51-52 | 37 |
4xl | 54-55 | 37 |
Chest Widest part of chest
Sleeve Center back of neck to shoulder seam to sleeve hem edge
Fit Information
Standard True to Size | Active Layering
Expedition Oversized | Static Layering
Learn more about our layering systems
System Builder