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  • Breathable merino wool is naturally warm when it's cool and cool when it's warm
  • Moisture-wicking, quick-drying jersey knit offers UPF 30
  • Seam-free shoulder panels for comfort under pack straps
  • Works as a base layer or on its own
  • Chafe-free flatlock seams
  • Heat-transfer logo on left cuff
  • Formfitting


View all Smartwool Men's Long Underwear Tops

REI membership


Best Use Multisport
Shirt Style Crew
Fabric Merino wool
Sun-Protective Fabric Yes
UPF Rating 30
Moisture Wicking Yes
Quick Drying Yes
Underwear Weight Ultralightweight
Sleeve Length Long Sleeve
Gender Men's

Size chart

Rated 5 out of 5 by from Perfect for those in between days Recently purchased this item and wore it out on the range under my shooting vest on one of those in between days where a little warmth is needed as well as protection from the sun. Did not overheat and did not feel the chill. Good athletic fit.
Date published: 2016-04-23
Rated 5 out of 5 by from Go to product Good quality and fits well. 5'11 175 wear a large. Go to base layer during spring and fall backpacking on the AT.
Date published: 2016-10-18
Rated 5 out of 5 by from warm, easy washed, no body odor after use I wear this with my sports jackets in the winter. cool and feels great. bought two. love them
Date published: 2016-01-09
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Should I order the normal size worn in a tshirt or up a size? 

Asked by: kimjo71
​We recommend you order your normal shirt size.
Answered by: REIservice
Date published: 2016-12-05

How much does it weigh?

Asked by: Astro1
The NTS Micro 150 Crew Long Underwear Top weighs 7 ounces.
Answered by: REIservice
Date published: 2016-05-26
  • y_2017, m_4, d_24, h_7CST
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