A heavyweight merino base layer top designed to help regulate temperature during high-intensity activity, the 260 ZoneKnit Long Sleeve Half Zip is the ideal choice for cold-weather training and adventures when you’re moving fast. Made with 100% pure merino wool for all-natural breathability and odor-resistance, the ZoneKnit also features strategically placed panels of eyelet merino mesh to help actively regulate body temperature, and a half-zip design for easy on/off and quick heat dumps. Raglan sleeves and gusseted underarms provide enhanced mobility, and flatlock stitching eliminates chafing. Inspired by nature, icebreaker harnesses the performance qualities of natural fibers to offer an alternative to clothing based on petrochemical synthetics. Merino is an annually renewable fiber that naturally resists odors, keeps you cool when it’s hot and warm when it’s not, and lets your skin breathe for comfort all day, every day.