Smartwool's Women's Intraknit(TM) Thermal Max Merino Base Layer 1/4 Zip. This bulk-free, 100% Merino wool thermal layer brings a new dimension to active winter wear. With seamlessly integrated insulation and ventilation, perfectly articulated flex zones, and Merino wool comfort, it'll be the first thing you grab when you need a warmer layer for your high-intensity, cold-weather adventures. Design: Intraknit(TM) Thermal Max Merino: Intraknit(TM) technology is helping revolutionize the base layer industry. Including 3D-mapping for a custom fit, durability, and freedom to move. Slim fit is intended to follow the contours of the body Featuring Intraknit(TM) technology: Insulation, articulation, and ventilation are seamlessly integrated to help with movement and comfort 100% Merino yarn provides the full power of Merino with moisture management, insulation, thermoregulation, and odor control Insulating terry loops are seamlessly paired with mesh ventilation in gender-specific zones to help balance warmth and breathability 3D mapping results in near custom fit and freedom of movement Additional Details 8.25" (21 cm) center-front zipper Made in India: 100% Merino Wool. Exclusive of Decoration.