evo.com | Smartwool Long Underwear Bottoms > All great days start by slipping into a solid base layer. The Smartwool Classic Thermal Merino Base Layer Bottoms make it easy with full-length 100% merino coverage for the coldest of days. And with an updated fit to improve functionality, this is one long john you won't want to leave the house without. Slim Fit Flatlock Seam Construction Designed to Eliminate Chafing Fabric Weight | Mid 250 Single layer for cold weather performance. Baselayer for very cold weather. Merino-Covered Elastic Waistband 100% Merino Wool Made with an interlock knit for enhanced comfort, breathability, thermoregulation, and odor resistance. | Smartwool Classic Thermal Base Layer Bottoms Men's 2026 - Large Blue