REI Co-op Lightweight Base Layer Long-Sleeve Crew Top - Men's

REI Co-op Base Layers

REI Co-op Sahara Long-Sleeve T-Shirt - Men's

Smartwool Merino 150 Crew Base Layer Long-Sleeve Top - Men's

REI Co-op Midweight Base Layer Half-Zip Top - Men's

REI Co-op Midweight Base Layer Crew Top - Men's

Lightweight Base Layer Tops

REI Co-op Midweight Base Layer Crew Top - Men's

REI Co-op Men's Base Layer Tops

Lightweight Base Layers

REI Co-op Lightweight Base Layer Half-Zip Top - Men's