Uphill, downhill, or just standing around, the women's Burton Phayse Quarter-Zip Base Layer sets the standard for temp regulating comfort. 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, easygoing feel. FEATURES: Designed to maximum warmth with minimal weight for both on- and off-snow activities. Strategic fabric placement for Warmth and Breathability where you need It. Venting Mesh Piecing. Stretch 360° For Unlimited Mobility Chafe Free Chin Guard, Chafe-free Softlock Seams for Comfort Double Needle Stitching on Sleeves and Hem Merino Single Jersey, using Rapt Yarn 87% Merino/13% Nylon (16.5 Micron) Pieced with Venting Mesh ReRAPT Yarn 49% Merino /51% Nylon. Locker Loop.