Smartwool Men's Classic Thermal 250g Merino Baselayer Bottom Black Size:XL Lining: Recycled polyester and nylon

Lining: Recycled polyester and nylon used for linings

The Smartwool Men’s Classic Thermal 250g Merino Baselayer Crew Top sits close to the body with a slim fit that layers smoothly under insulation and shells without excess bulk

The fabric balances warmth and breathability for consistent comfort through cold starts and high-output laps

A Performance™ Core combines Aspen

interior power mesh dump pockets

Smartwool Men's Classic Thermal 250g Merino Baselayer Bottom Black Size:XL Lining: Recycled polyester and nylonWarmest weight 100% Merino wool delivers consistent insulation with natural moisture management, temperature regulation, and odor resistance, all built into a smooth interlock knit that stays comfortable during high output days. Flatlock seams reduce friction, while a Merino lined elastic waistband maintains soft, secure comfort under packs and shells. Cut with a slim, body hugging fit, the Smartwool Mens Classic Thermal 250g Merino Baselayer Bottom