Meet the Men'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 comfort, it 'll be the first thing you grab when you need a warmer layer for your high-intensity, cold-weather adventures. Smartwool Intraknit(TM) Thermal Max Merino Base Layer 1/4 Zip Mens | Black | X-Large | Christy Sports