Nike Dri-Fit Knit Womens Running Tank / Sleeveless Top 100% Polyester Dri-FIT/STAY COOL fabric wicks away sweat and helps keep you cool, dry and comfortable Knit-in mesh panels in high-heat zones enhance breathability to help you stay cool Racer back design for excellent range of motion Lightweight seamless construction, made of nylon and polyester yarns, feels smooth against your skin to help reduce distractions as you move Reflective loop at upper back to keep media-player cords out of the way