This outstanding top blends our two fabulous Zone 3 fabrics, 3SP® and SwiftPro™ for unbeatable performance and plenty of reflectivity. The 3SP® on the front and arms blocks the wind up to 35 mph and dries faster than any fabric on the planet. Soft, comfortable quick-wicking SwiftPro™ is found under the arms and on the back to help regulate temperature. It has a 13-inch reflective front zipper, reflective tape on key seams, and a large back zippered pocket. Great for nordic skiing, cycling, running, and hiking. Simply said, we think it's the best technical winter top available for aerobic athletes. Windproof up to 35 mph.