. . The Tight Crew Short Sleeve Shirt from 5.11 Tactical is built from a poly/spandex blend to provide a compressed fit for maximum performance in any. . environment. A saddle-shoulder design ensures complete freedom of movement during periods of high activity, and the Tight Crew excels under body armor,. . making it equally suited to the gym or as your TDU bottom layer. Built from anti-microbial, moisture wicking, quick drying fabric, the Tight Crew. . incorporates mesh vents under each arm to ensure maximum ventilation, keeping you cool, comfortable, and in control all day long.. . Durable, comfortable and functional. . Compressed athletic fit. . Moisture wicking technology. . Underarm mesh panels. . Wears well under body armor. . 82% polyester, 18% spandex. . Saddle-shoulder design. . Anti-microbial, quick-dry fabric. . Flat-lock Seams for comfort. .