The bulk-free, Women's INTRAKNIT Merino 250 Termal ¼ Zip from Smartwool brings a new dimension to active winter wear. This 100% Merino wool thermal layer features seamlessly integrated insulation and ventilation for lightweight breathability, that wicks moisture, and repels odour. The perfectly articulated flex zones and 3D mapping provide a custom fit that gives you a full range of motion. The durable ribbed elbows and knit-in reflective elements are just some of the details that combine to give you durable performance in soft Merino comfort.