Merino 365
Men's Midweight OG Long Sleeve - 100% Merino Wool, Black
Men's Midweight OG Long Sleeve - 100% Merino Wool, Black
In stock
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These are the perfect merino base layer pants. I'm 173cm tall (5'8") and got the 2XL-- the pants are not too long, and they'd still work for taller people. The fit is fantastic and they're so breathable. I'm usually on the warm side, and until I got these pants, I wore shorts around the house, but now I wear these all the time! I raved about them so much that my partner ordered one herself (along with a top). I'll continue to tell friends and family about Merino365, and I'll be buying more products from them in the future.
This 1/4 zip top has become my everyday top in cool and cold weather. I'm 173 cm tall (5'8"), so the sleeves fit nice and relaxed. It's so soft and warm, and it doesn't fit skin-tight like many other brands. It's relaxed enough to wear every day, but it's also perfect as a base layer under mid and shell layers. Shipping was smooth to the U.S. I highly recommend Merino365! Fantastic business!
Bought two of the OG long sleeve for our family trip to Europe.
We are currently in Muonio, Lapland, 275km north of the Arctic circle ❄️❄️ and they have kept me toasty and warm!
We are supplied with extreme weather gear for the conditions, but it all starts with the right base layer - these are great.
10/10 recommended.☃️
I've worn this and it's so cozy. Quality is really good and the customer service was top notch. I would highly recommend Lucy and her products at Merino 365
Size correct; perfect fit
- Easy returns
- Timeless Fit
- New Zealand merino
Same OG, just heavier. The Midweight OG is your cold-weather upgrade—built with the same trusted design as our original OG Long Sleeve, but in a warmer, more substantial 230gsm merino. Ideal for chilly morning runs, winter hikes, or throwing on after a cold plunge.
Features
- 100% New Zealand Merino Wool – 230gsm
- Fine micron: 20 micron for softness ideal for over our t-shirt - preferred as a 2nd layer
- Midweight warmth with zero bulk
- Breathable, moisture-wicking and naturally odour-resistant
- Regulates body temperature in cold or fluctuating conditions
- Moves with you – stretch and recovery built in
- Ideal as a standalone or cold-weather base layer
- Designed in New Zealand, made in China or Fiji
- Easy care – machine washable on wool cycle
Description
For the colder months—or for those who simply run cold—the Midweight OG is your merino MVP. At 230gsm, it delivers a little more insulation than our standard OG, without compromising on breathability or comfort.
Soft, itch-free and naturally temperature-regulating, this long sleeve adapts to your environment and activity. From winter trail runs and backcountry hikes to layering under a jacket for the daily commute, it’s built to perform and made to last.
If you’re after a one-and-done merino top for cooler conditions, this is it. Same cut, same trusted fit—just a little more muscle.
Fabric & Care
- Fabric: 100% Merino Wool, 230gsm
- Micron: 20 ( 2nd layer soft)
- Care: Machine wash cold on wool/delicate cycle with wool detergent. Lay flat or air dry.
- Origin: Made in China or Fiji using NZ merino
Why Merino 365?
Born in New Zealand, tested by nature. We use only the highest quality merino wool—engineered for performance, made for daily wear. No synthetics, no compromises. Just natural comfort, 365 days a year.

I love clothing gear and have tested just about every type and brand. I have several of these Midweight OG long sleeve tops because they are the best I have found. I don’t hike or camp anymore, but I walk 3 miles a day, every day no matter what the weather. I’m 76 years old and I dress to be comfortable even if it’s 10° outside.
Great I didn't take it off for days.
Comfortable
So good, washes well, very warm.
Lovely quality merino, love the thumb loops. Could do with a bit extra length.