One of the very best things about the Women's Tech Long Sleeve Half Zip is that it provides excellent warmth to weight, but also breathes really well. So when you heat up and then cool down during active pursuits, you'll stay completely comfortable. The midweight merino fabric is very soft against the skin, and the Tech Long Sleeve is engineered for comfort in mountain sports. Offset shoulder seams and forward side hems eliminate chaffing and discomfort under a backpack, and the set in sleeves aid arm mobility. If you get too hot, the half zip front provides instant ventilation. And the elliptical hem adds a nice style detail that makes the Tech Long Sleeve great for everyday wear as well. Best of all, merino's natural odor protection make it the one shirt you can wear day after day on your action packed vacation.