Trail running, jogging or mountain biking, the Mens Flyweight Jacket gives you the basic protection you need for fast paced sports. Jack Wolfskin's breathable Flex Shield AirLite fabric is extra light and stretchy; it regulates your body temperature and follows every move you make, so it always feels great to wear during outdoor training sessions. When the weather is constantly changing between sun, wind and showers, the flyweight will keep you dry and agile. It also packs down to nothing so it will fit in your waist pack. And during evening training sessions the reflective detailing ensures you stay visible.