HeatGear® fabric is ultra-soft & smooth for extreme comfort with very little weight; Stretch-mesh back panel delivers strategic ventilation; 4-way stretch fabrication allows greater mobility in any direction; New Fit: +1" Across Waist, +½" Sleeve Length; Moisture Transport System wicks sweat & dries fast; Anti-odor technology prevents the growth of odor causing microbes; Locker loop makes it easy to hang; 100% POLYESTER