Underwear Tops
Lightweight Base Layer Half-Zip Top - Men's
REI Co-opFirst half-mile cold; next 3 miles sweaty; lunch break cold. Don't stress—the REI Co-op lightweight half-zip long-sleeve base layer wicks and breathes to keep you comfortable all day.
Lightweight Base Layer Half-Zip Top - Women's
REI Co-opThe women's REI Co-op lightweight half-zip base layer top wicks and breathes to keep you comfortable hiking or skiing as you go from cold to warm to overheated and back.
Lightweight Base Layer Half-Zip Top - Women's Plus Sizes
REI Co-opThe women's plus-size REI Co-op lightweight half-zip base layer top wicks and breathes to keep you comfortable cold-weather hiking or skiing, as you go from cold to warm to overheated and back.
Lightweight Base Layer Long-Sleeve Crew Top - Men's
REI Co-opThe men's REI Co-op lightweight long-sleeve base layer crew keeps you warm until you warm up, then wicks sweat to keep you comfortable when you're going hard.
Lightweight Base Layer Long-Sleeve Crew Top - Men's Tall Sizes
REI Co-opWhat could possibly keep you warm until you warm up, then keep you comfortable when you start sweating on the trail? The men's tall REI Co-op lightweight long-sleeve base layer crew is what.
Lightweight Base Layer Long-Sleeve Crew Top - Women's
REI Co-opComfy as you warm up, comfy as you cool down, even comfy when you break a sweat—the women's REI Co-op lightweight long-sleeve base layer top is ideal for skiing, hiking and lunch break, too.
Lightweight Base Layer Long-Sleeve Crew Top - Women's Plus Sizes
REI Co-opThe women's REI Co-op long-sleeve lightweight base layer crew top wicks, breathes and stretches for comfort through every temperature change as you hike or ski the day away.
Lightweight Base Layer Long-Sleeve Zip-Neck Top - Men's Tall Sizes
REI Co-opThe REI Co-op lightweight base layer zip-neck top in men's tall sizes knows how to keep you comfortable through a whole day of changes from cold to warm to sweaty and back to cold again.
Lightweight Crew Long Underwear Top - Infants'/Toddlers'
REI Co-opStart layering your little ones with the toddlers' warm, breathable REI Co-op Lightweight Crew Long Underwear top. It features a made-to-move design and all of the comfy for a day of play.
Lightweight Crew Long Underwear Top - Kids'
REI Co-opStart layering your littles with the kids' warm, breathable REI Co-op Lightweight Crew Long Underwear top. It features a made-to-move design and all of the comfy for a day of play.
Logan Half-Zip Long-Sleeve Base Layer Top - Men's
LoleWhen it comes to base layers, basic is better. The men's Lole Logan half zip is a long-sleeve base layer top that's perfect under your gear for outdoor training or activities, or for everyday life.
Lucie Long-Sleeve Base Layer Top - Women's
Kari TraaProviding lightweight warmth and natural temperature regulation, the Kari Traa Lucie Long-Sleeve base layer top is made from fine merino wool and designed to layer smoothly under your jacket.
Merino 150 Lace V-Neck Base Layer Top - Women's
SmartwoolWhether you wear it on its own or as a base layer, the women's Smartwool Merino 150 Lace V-Neck short-sleeve top is designed for comfort when you're on the move.
Merino 185 Base Layer Top - Men's
REI Co-opHike, bike and even sleep in the men's REI Co-op Merino 185 short-sleeve base layer top. The soft, breathable and naturally odor-resistant ultrafine merino wool makes it an ideal next-to-skin layer.