Men's Base Layers

Our Men's Classic Thermal Merino Base Layer Bottom just got an upgrade; now it fits better, and its technical performance promises you'll be abl...

An ultralight merino base layer top designed to help regulate body temperature during high-intensity activity, the 125 ZoneKnit™ Long Sleeve Crewe ...

Our versatile, go-anywhere shirt made from breathable 100% merino wool jersey, the 200 Oasis Long Sleeve Crewe is our best-selling base layer top.

A heavyweight merino wool base layer for highly aerobic days in cold weather, the 260 Zone Long Sleeve Half Zip features zoned ventilation panels f...

A warmer, midweight version of our best-selling Oasis, the 260 Tech Long Sleeve Half Zip is a go-to piece for winter layering, made with 100% merin...

Icebreaker's technical, cold-weather base layer top for highly aerobic days, the 260 Zone Long Sleeve Crewe features zoned ventilation panels for ...