Engineered for the most demanding athletes in the toughest conditions, the men's Artilect Darkhorse 185 Zoned base layer top get you in the zone with lightweight and durable merino wool.

Underwear TopsBase Layer Tops

Offering superior temperature regulation without the bulk, tasc Performance Elevation Merino men's base layer bottoms deliver light warmth and moisture management for cool-weather outdoor activity.

Underwear BottomsBase Layer Bottoms

You can stop looking for that ideal base layer. The tasc Performance Elevation Merino men's T-shirt offers superior temperature regulation and moisture management without the bulk.

Underwear TopsBase Layer Tops

Designed not to roll, ride up or constrict, the 3 in. inseam Patagonia Essential boxer briefs keep you comfortable from sunrise to sunset, with breathable, supersoft and chafe-free fabric.

UnderwearUnderwear Bottoms

The 6 in. inseam Patagonia Essential boxer briefs keep you comfortable all day long with supersoft, chafe-free and breathable fabric and a design that never rolls, rides up or constricts.

UnderwearUnderwear Bottoms

Supersoft, chafe-free and breathable fabric combines with a bulk-free fit and anti-roll waistband to make the Patagonia Essential boxers your go-to for all-day comfort.

UnderwearUnderwear Bottoms

Our outdoor expertise doesn't stop at zip-off pants. The men's REI Co-op Everyday boxer briefs are built to traverse crags and run trails—or sit super comfortably while you plan those things.

UnderwearUnderwear Bottoms

Our outdoor expertise doesn't stop at zip-off pants. The men's REI Co-op Everyday boxers are built to climb mountains and run marathons—or sit super comfortably while you plan those things.

UnderwearUnderwear Bottoms

Our outdoor expertise doesn't stop at zip-off pants. The men's REI Co-op Everyday briefs are built to run trails and traverse mountains—or sit super comfortably while you plan those things.

UnderwearUnderwear Bottoms

Purpose-built for advanced insulation and unrestricted mobility, the men's NRS Expedition Weight base layer shirt layers seamlessly under drysuits, helping paddlers hit the water in cold conditions.

Underwear TopsBase Layer Tops

When conditions call for maximum insulation, the men's NRS Expedition Weight union suit delivers. Cozy yet breathable, this paddling-specific design offers unrestricted mobility even under a drysuit.

UnderwearUnion Suits

As solid and dependable as its namesake rock formation in Colorado, the men's Artilect Flatiron 185 crew is durable yet comfortable and made for effortless, reliable performance in harsh conditions.

Underwear TopsBase Layer Tops

An ideal base layer for getting vert or counting off switchbacks, these men's Artilect Flatiron 185 leggings provide soft, breathable warmth while you explore outdoors.

Underwear BottomsBase Layer Bottoms

Offering up personalized comfort, the men's Artilect Flatiron 185 Quarter-Zip base layer top gives you warm, fast-drying wool and a zipper that lets you vent or add heat to your core.

Underwear TopsBase Layer Tops