Perfect for chilly early morning or evening runs, the Nike Flash Men's Long-Sleeve Running Top helps keep you warm without overheating. Reflective graphics on the arms help you stand out.  Keep Cool, Stay Warm Throughout the back is a more open knit for breathability, helping to keep the fabric from clinging to your skin. A half-zip design lets you adjust for the right amount of ventilation, while allowing you to keep covered when you transition to post-run plans. Move Freely Thumbholes keep the sleeves from shifting or flapping in the wind and add a little more coverage in cool weather. Raglan sleeves and seams that follow the shape of your arm allow you to move naturally. Stay Dry The soft fabric features Dri-FIT Technology that wicks sweat away from your skin to the fabric's surface where it quickly evaporates.