Get Techy With Merino The men's Burton Phayse Merino Quarter Zip Base Layer is not your average base layer. It's the lightweight merino blend yarn that sets it apart from the crowd and gives it real-world breathability and comfort credentials. Wear it riding. Wear it hiking. Wear it anytime you need lightweight, low-profile warmth. Any which way, it has you covered with all-natural temp regulation and a soft, easy going feel. Merino wrapped nylon core yarn puts 100% merino against the skin for natural temperature regulation, breathability, and stink-free comfort. The nylon core adds strength for long-term fabric durability. FEATURES: Next to Skin Fit Chafe Free Chin Guard Locker Loop Double Needle Stitching on Sleeves and Hem Vented: Merino mesh panels add extra breathability where you need it most Venting Mesh Piecing Merino Single Jersey, using Rapt Yarn Stretch 360degree 87% Merino 13% Nylon (16.5 Micron) Venting mesh: 49% Merino /51% Nylon Lifetime Warranty