Smartwool Intraknit™ Merino 200 Colorblock Crew Women's base layer. made with Merino wool to help with moisture management, temperature control, and odor resistance. Mesh layers for breathability. Material 52% Wool, 45% Polyester, 2% Elastane, 1% Polyamide Merino Sport Yarn: Combines the power of Merino with the durability and fast dry times of polyester.