Men's ColdGear® Base 4.0 Crew

Style # 1353349
Height: Size: Fit: Fitted
Mens ColdGear® Base 4.0 Crew
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Size and Fit Guide
Due to limited quantities, only 100 allowed per customer.
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Height: Size: Fit: Fitted
Men's ColdGear® Base 4.0 Crew

Product DNA

UA Base 4.0 is a men's baselayer built for extreme cold weather and lower activity. It uses a unique pattern that's designed to trap heat without adding bulk. Think long underwear, revamped for today's top athletes.
  • Fitted: Next-to-skin without the squeeze
  • UA Base™ 4.0 Extreme Baselayer is our warmest yet, locking in your body's heat to deliver extreme warmth in the extreme cold
  • UA Scent Control Technology to keep you undetected in all pursuits
  • Soft, brushed grid interior traps air against your skin, closely managing your body's microclimate to keep you warm & comfortable
  • Material wicks sweat & dries really fast
  • 4-way stretch construction moves better in every direction
  • 78% Polyester/22% Elasterell
  • Style #: 1353349
  • Imported

Review Summary

29 Reviews


Runs small Runs large


Min. Max.


Min. Max.

Comfortable, functional and looks great.

Comfortable, functional and looks great. Fabric is soft and yet strong. Fit-for-purpose. Looks good and feels great. Keeps you nice and warm.

I use it for winter biking very warm.

[This review was collected as part of a promotion.] Cozy. Holds heat well. Want to use in North Dakota with high winds to see if it’s legendary 4.0 status holds to what is expected. Probably will, you can buy 4.0’s in that region quite easily. Which is what prompted me to order mine online. For winter weather biking.

Buy if you're a collector of Under Armour items

I was sad to see that the negative reviews were true. About 70% of all my clothes are by Under Armour, and I have about 10 of the old style (both the squares and the chevrons) 4.0s that I have been wearing for many years and they are still holding up. This new one is at most as warm as a 2.0. I do not know why they changed the design and quality, but it's very sad to take away a product so superb and so popular and replace it with a lower quality, probably lower cost but same price alternative. In addition to the product thickness and quality, the shape seems to have changed as well. It feels like it's no longer 'athletic'. It's more 'tubular' and is extremely long - wondering how I can even tuck this in my pants with the excess baggage it now has. If you're a die hard under armour fan like me, go ahead and and get one, just to have one in your wardrobe as a souvenir, but not for cold performance. Otherwise, very questionable purchase.

poor quality

I purchased several UA base for my husband this year. I have the older version 4.0. When I received it, I was shocked to see the shirt is so thin that is not even close to the old version. Will return them all.

Sleek light weight and comfortable.

It’s the best iv ever bought. This base .04 is the ticket to enjoying every hunt without getting cold. I own nothing else to hunt or just walk the woods.

No good at all

Used to have a pair before so I got new ones they are crap don’t keep you warm at all a 15 dollar pair of Hanes thermal works better then these do don’t waste your money on them took mine back and got Hanes thermal works a lot better

Favorite Christmas gift

My son-in-law looks forward to the Under Armour gifts each year. They are his favorite.


I climb cell phone towers so there are times where a lot of movement is required and times where you sit in place for hours. Its usually extremely windy and extremely cold during the northern winters while hundreds of feet in the air. I was wondering which base layer would be the best fit?

Super warm

Amazing...I didn't think something that was so light weight could be this warm. Great fit and look. thx

old school 4.0 vs 4.0 new school sucks

old school on their armor with waffle design was the warmest stuff I've ever worn in my life this new under armor ain't worth the money your time or the company's effort to make such a false claim to be the warmest yet I'll take the old school stuff over this new school stuff any day you lost a valued customer