This wind resistant vest is developed for trail running but will work great for all outdoor activities where you need wind protection in the front and breathability in the back. We use a arero90 fabric in the vest because it offers a great mix of wind resistance, breathability, packability and durability. We use an open mesh fabric in the back for breathability and fit. The main fabric is 100% recycled 20d nylon, 49g/m2. The open mesh is made of 86% recycled nylon /14% elastane, with the weight of 145g/m2. Main features include: elasticated arm holes for a good fit, brushed interior fabric inside neck, reflective stripes and logos, chest pocket, zippered back pocket with a concealed belt. When turned inside out, the pocket becomes a pack to store the jacket in and attach around your waist when not in use. This vest has a slim fit that is slightly longer in the back.