The icebreaker 260 Tech Long Sleeve Half Zip will be your go-to for winter layering. From running and hiking to skiing and snowshoeing, you can wear this versatile half-zip for just about anything. The weight is perfect, the style goes with any outfit and its merino wool construction is the perfect combination of breathable and warm. Details: 100% Merino - Soft merino fibers regulate body temperature in all weather conditions and resist odors Gusseted underarms for mobility and comfort Offset shoulder seams to prevent friction Flatlock seams to prevent friction Backward set side seams to prevent friction