XGO's innovative base layers have been tested at the highest activity levels. XGO Men's Montana Wool 1.0 Crew is a high-performance lightweight 100% merino wool Longsleeve Crew. XGO merino wool is sheered and made from sheep sourced in the United States. Constructed with XGO patented Acclimate Dry moisture-wicking/quick-drying technology, guaranteed to provide absolute moisture-management treatment. Lightweight, breathable & natural No Melt/No Drip. Exclusive Clean Seam next-to-skin comfortable promotes unrestricted movement with unlimited range of motion.