X-BIONIC Symbio Merino Base Layer combines ultra-fine merino wool with advanced sweat-management technology to regulate temperature and support performance on cold-weather activities. Key attributes: Black | Merino wool | Thermoregulation | Enhanced breathability | Keeps wearer dry and warm | Targeted insulation | Moisture management | Muscle support and mild compression | ISO-Pads for targeted insulation | Expansion ribs for mobility | 3D Bionic Sphere System® zones | Dimensions & fit: Compression level: 03/05 | Size range: XS–XXL | Composition & care: 84% Wool (Merino) | 14% Polypropylene | 2% Elastane | Machine wash max 30°C mild process; do not bleach; do not tumble dry; do not iron; do not dry clean.