A midweight baselayer zip shirt with optimized venting zones for active performance, the Men's Winter Zone Long Sleeve Half Zip is a technical top for highly active days in cold conditions. Fully functional for warmth, ventilation, and support while alpine climbing, backcountry skiing, or other day-long adventures in the wild, the body features 260gm merino wool fabric with a touch of LYCRA® for stretch and a deep front zip for easy heat dumping. In the underarm panels they used lightweight, 180gm eyelet merino mesh that actively controls temperature during high-output pursuits, and in the higher-wear areas around the elbows and forearms they added 230gm merino and polyester waffle jersey for added abrasion resistance. Flatlock seams throughout eliminate chafing during fast-paced days. Fabric:  260gm face fabric, 230gm arms/lower back, 180gm mesh panels. Main: 260gm, 97% Merino wool, 3% LYCRA. Mesh: 180 gm, 98% Merino wool, 1% LYCRA, 1% Nylon. Arms and lower back:  230gm, 78% Merino wool, 22% polyester            Benefits: Warmth, breathability, comfort, stretch, odor resistance Icebreaker BodyfitZONE®, zoned panels for warmth and breathability,  deep venting front zip, flatlock seams prevent chafing