100% Merino Wool
Here's what other sites are saying:
There are more than twice as may sheep as people in Iceland. Maybe that's why the people at 66 North Iceland dig merino wool so much. They used the wunder fabric to create their high-end long underwear bottoms, the Men's Basars. These non-itchy base layer bottoms take advantage of Mother Nature's best tech-merino breathes well, manages moisture, and retains heat even when wet. For easy layering, 66 North Iceland gave the Basars an athletic fit, elastic waist, and flat needle stitching.
- Backcountry Outlet