This Tight Fit 5.11 undergear shirts are designed to be worn under body armor. Provide support for a long workday. Key design features include a saddle- shoulder construction. An underarm mesh panel that allows moisture to vent and evaporate easily. And flat-lock seams that reduce friction in order to prevent chafing. Undergear is made out of 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, Affordable enough for everyday wear.