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Swift Tech Mockneck LS

Swift Tech Mockneck LS

Thermoregulating, moisture dispersing technical base layer with odor resistance

M's Swift Tech Mockneck LS in Atlantic
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free shipping over $55
free 60 day exchanges
Aron wears size M and is 5'11" Slim fit, Size Chart

The Swift Tech Mockneck LS is a an ultra-soft, moisture-wicking, alpine inspired base layer with the enhanced benefits of merino and Polygiene® anti-odor control. Designed for repeat use between washes, you can wear it as a stand alone top or as your bottom layer. Read more

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Moisture-wicking comfort
Ultra-soft, thermoregulating merino/poly jersey provides fast moisture-wicking management to quickly move sweat + heat away for comfort during prolonged efforts

Stays fresher longer
Polygiene® permanent anti-odor control keeps the fabric fresher for longer, so you can use it more between washing — reducing water + energy consumption

Quick dry
DriRelease jersey speeds up dry times

Wear it on its own or as a base
A snug but not skin-tight fit makes for super easy layering and wearability on its own

Ergonomic seaming
Contoured arm hole with racerback seams allow for freedom of movement

Alpine inspired styling
Mockneck style adds extra neck protection with our signature tonal ladder stitch on back

Better thumb slits
Integrated thumb slits built into the cuffs essentially disappear when not in use

Hang it up
An elastic locker loop is integrated into the back collar 

materials + specs

Swift Tech with Polygiene® anti-odor control
84% polyester, 11% merino, 5% spandex drirelease

194g / 6.8oz (M's Medium)

Garment made in Vietnam


Swift Tech is treated with Polygiene® anti-odor control to inhibit and prevent the growth of bacteria that causes stink. Studies show that washing and caring for garments makes up 2/3 of the environmental footprint over the lifespan of apparel — by wearing more and washing less, even just wearing something twice between washes, can save energy and water, reduce CO2 emissions and minimize micro-plastics.

Swift Tech is also OEKO-TEX® certified meaning it is free from harmful chemicals and is fabricated in a way that meets a high environmental standard.

Learn more about our sustainable initiatives here.


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Customer Reviews

Based on 28 reviews
Joel P.
Great for cool to cold weather!

Love this LS from Janji! Material is cozy, fit is dialed in and now that I have experienced “mock neck” there’s no going back to a loose collar, especially while running in the cold!

Anthony p.
My Janji preferred

This mock neck is my favorite Janji gear I own. I have trouble finding things that fit. I’m 6’2 180 with a long torso and the large fit like perfectly, including length. It’s warm and It’s also used it as a lounge piece.

Amazing top

I’ve been living in this piece all winter. Super soft and comfortable. Love it!

Tim L.
Versatile Base Layer

I just received my Swift Tech Top base layer. Ran for an hour in 25 degrees and flurries paired with a Stormrunner Fleece. Warm and softer than typical base layer poly based products . Just awesome! Will definitely wear this casually as well.

Great base layer

I bought this for my husband and he loves it. It is super lightweight, and it wicks well. He's worn it for running, cross country skiing, and hiking high peaks. Really a great piece of clothing.

Steve M.

I don’t write many reviews, but this is the first piece of clothing that made me say ‘holy sh*t’. I’ve run in the shirt three times in mid-20s weather with just a windbreaker shell and I was almost too warm. If you want a good cold weather base layer, buy this shirt.

Phu P.
My Favorite

I love these. Soft and smooth. They feel great running in and lounging around. Sizing is exactly as described. I would love to have this in more colors. The cut is excellent. Not too loose. Not too tight.

Mark F.
MockNeck is Fantastic

This was my second purchase from you. I have ordered the same product twice now, in each color you offer.

Unfortunately, I was not able to enjoy Black Friday price reductions in the second order, made about 5-days before you offered discounts.

I feel like a silly consumer.

Jeffrey M.

M's Swift Tech Mockneck LS in Astral


M's Swift Tech Mockneck LS in Atlantic