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.. Features:. Soft knit fabric with engineered mesh ventilation, mapped to the places you need it most. Nearly sew-free design to eliminate chafing. 4-way stretch material moves better in every direction. Material wicks sweat & dries really fast. Wide scoop neck for easy layering. 90% Nylon/10% Elastane. Fitted: Streamlined fit that’s not too tight or too loose.