Affordable enough for everyday wear, our Tight Fit 5.11 Undergear shirts are designed to be worn under body armor and to provide support for a long workday. Key design features include a saddle- shoulder construction that offers greater range of motion, an underarm mesh panel that allows moisture to vent and evaporate easily, and flat-lock seams that reduce friction in order to prevent chafing. 5.11 Undergear is made out of our moisture-wicking, anti-microbial and quick-drying fabric. Available in short- and long-sleeve crews and short-sleeve v-necks. 80% polyester, 20% spandex fabric. Imported.