Affordable enough for everyday wear, Tight Fit 5.11. Undergear shirts are designed to be worn under body armor. Pprovide support for a long workday. Key design features of this shirt are saddle shoulder construction. An underarm mesh panel that allows moisture to vent and evaporate easily. Flat-lock seams that reduce friction in order to prevent chaffing. Undergear is made out of Dri-X-treme moisture-wicking, anti-microbial and quick drying fabric. Available in short sleeve and long sleeve crew necks and short sleeve v-necks. 80% polyester, 20% spandex fabric.