While the S1 Run Jacket is made from a wind and water-resistant material that is ultra-lightweight and ventilating due to the jacket`s stretchy side panels. This provides the jacket with a comfortable fit combined with optimal protection from wind and precipitation during your run. It is suitable for the exact type of protection you need during your run for most of the year - just adjust the insulation according to the weather with the layer you choose underneath. The running jacket`s stretchy side panels ensure a comfortable running experience and efficient ventilation in the moderately close-fitting jacket. The inside of the collar is soft and sweat-wicking. The jacket has a robust YKK zipper with a windproof back and a zippered front pocket with an elastic back that adapts to the contents of the pocket - such as a phone and cards. Discreet but secure 3M reflective bands on the sleeve and front and back of the shoulders ensure 360-degree visibility during dark hours. Optionally, choose the jacket in Hi-Vis for increased safety.