* 4 SEASON BASE LAYER. Spring skiing or summer camping? This base layer is designed for both due to the versatility and temperature-regulating properties of our Merino fabric, enhanced with Core Spun technology for increased durability. * SLIM FIT. Designed to meet the demands of outdoor adventuring, this slim fit long sleeve shirt shows off a slimming silhouette while offering unrestricted movement through the arms and chest. * CLASSIC ALL-SEASON MERINO. Perfect for 4 season layering and everyday comfort, this ultra lightweight performance fabric blends Core Spun Tech that maximizes durability with the thermoregulation and moisture wicking power of Merino wool. * WHY MERINO WOOL? Thinner and softer than regular wool, it's easy to wear next to skin. Each fiber transports sweat away as a vapor (we tested it ourselves) and regulates body temperature to keep you cool in summer and warm in winter. * FUNCTIONAL FEATURES. Go far, feel good with thoughtful tech to keep you trekking comfortably merrow stretch stitching elevates comfort and range of motion while a raglan sleeve design eliminates the need for shoulder seams.