The MISSION VaporActive baselayer long sleeve top helps you maintain your optimal body temperature so you can maximize your peak performance. VaporActive, powered by patented 37.5 technology, rapidly evaporates and removes sweat keeping you ultra-dry and warm. Compression fit with smooth flatlock seam construction provides an increased range of motion. Embedded at the fiber level, the permanent technology is chemical-free, controls odor and is engineered to never wash out.Our VaporActive compression underwear, powered by 37.5 technology, is infused with permanent active particles that rapidly attract and evaporate sweat keeping you cool, dry and comfortable so you can maximize peak performance. - FIBER CONTENT: 81% Cocona® 37.5® Polyester, 19% Spandex - Patented 37.5 technology rapidly evaporates and removes sweat so you can stay ultra-dry and warm - Permanent technology engineered to never wash out - Compression fit - Odor control - Brushed interior for comfort and insulation