Smooth woven fabric with built-in stretch for greater mobility. UPF 30 protects your skin from the sun's harmful rays. Stain release materials keep blood, guts & dirt from soaking in. Material wicks sweat & dries really fast. Anti-odor technology prevents the growth of odor-causing microbes. Mesh-backed shoulder & underarm vents . Roll-up sleeve loop & button. Button-down collar.