Mizuno Running Men's Breath Thermo Stretch Crew Tee Body: 90% Polyester/10% Polyacrylate, top Panel: 87% polyester/13% Polyacrylate, Side Panel: 79% Polyester/14% Polyacrylate/7% Spandex Imported Superior moisture absorbtion Designed with Mizuno's "Virtual Body" technology" Breath Thermo changes body moisture to heat for overall warmth 2-way stretch Breath Thermo of optimal fit 4 Needle flat lock construction