Warm, thin and flexbile - Smartwool Merino 250 Baselayer 1/4 Zip - Men's

I bought this for my winter hikes. It worked great - warm, thin and great for my layering system. Breathability seems great. It never gets too warm! I used it at home on its own when I am not on the trail. Body odor smell-resistant really works too. :) And I ended up buying two more for my wife and my son. Now my daughter really wants one. Highly recommended.