Using levels of mesh mapped to your body, you get ventilation where you need it, plus the comfort of fewer seams. It's pretty much the most comfortable thing you'll ever train in. Soft knit fabric with engineered mesh ventilation, mapped to the places you need it most Nearly sew-free construction to eliminate chafing 4-way stretch construction moves better in every direction Material wicks sweat & dries really fast Raglan sleeves Style #: 1365626 Reflective details for low-light runs 52% Nylon/48% Polyester Imported Fitted: Streamlined fit that’s not too tight or too loose. Machine wash cold with like colors Use only non-chlorine bleach when needed Tumble dry low Do not iron Do not use softeners Do not dry clean