100% polyester ; UA Tech fabric is quick-drying, ultra-soft & has a more natural feel ; Moisture Transport System wicks sweat and dries really fast; Anti-odor technology prevents the growth of odor-causing microbes; Four-way stretch fabrication allows greater mobility in any direction; Improved Fit: plus 1 1/2' in body length, plus 2' across chest, plus 2' around bottom opening; Updated set-in sleeves; UA logo on top front chest and back neck; Updated version of style 1268475