Whether you're training on your bike, trail running, or hiking, the Gore Wear WIndstopper Base Layer Thermo Long-Sleeve Shirt gives you a lightweight layer of defense against the elements. The Gore Windstopper membrane is strategically placed to deflect the wind while unlaminated fabric allows air to flow in less exposed areas. The synthetic material wicks away perspiration and dries quickly to minimize chills--helping you regulate your body temperature throughout your workout.