The Smartwool Men's Intraknit Thermal Merino Base Layer Crew is a lightweight, super-moveable top, made for all of your most extreme cold-weather activities. With Merino wool yarns and gender-specific ventilation perfectly placed to maximize thermoregulation and breathability during high-intensity activities, it helps amplify moisture management, movement, and comfort. When you're in Smartwool's best base layers, you're ready for anything. FeaturesSlim Fit3D mapping results in near custom fit and freedom of movement while ribbed elbows provide added durabilityMesh ventilation seamlessly knit in gender-specific zones designed to keep the body dry and comfortableEngineered construction uses knit structures to enhance performance with lighter weights and cleaner finish