This MTR 141 Half Zip Longsleeve Tee by Mammut is a great technical longsleeve puts you in the driving seat. This half zip longsleeve is made from elastic Jersey material and features impressively quick drying stretch material. This prevents dangerous overcooling on strenuous and windy high altitude routes. In addition, the integrated ADAPTIVE system by HeiQ supports dynamic moisture management. In other words, the material adapts to the circumstances and regulates your body temperature while you are running.