The Merino Seamless Long Sleeve Base Layer is the holy grail of base layers. As cozy as your favorite pair of wool slippers, yet it transfers moisture like water going through osmosis. It's the perfect recipe for a cool-weather layer courtesy of its Merino and synthetic fabrics. So, when you need to remain consistently warm on chilly days, look no further than this cool-weather staple. - Merino and synthetic yarns are blended to create a soft, insulating, and moisture-wicking layer, while also retaining a compressive feel. - Fabric Content: 40% Merino Wool, 40% Polyester, 20% Polypropilene