Show off those muscles in the Smartwool Men's Intraknit Thermal Merino Base Layer Colorblock Crew. The engineered construction uses knit structures to enhance performance with a clean and lightweight finish. Mesh ventilation seamlessly knits in gender-specific zones to keep the body comfortable and dry. The 3D mapping creates a near-custom fit and freedom of movement while ribbed elbows provide extra durability. This slim-fit top is constructed with soft Merino wool, polyester, and elastane for stretch.