Castelli Fly Jack-sey jacket: for the most demanding cyclists The Castelli Fly Jack-sey jacket is a high-quality garment designed for the most demanding cyclists. This jacket combines a light, breathable fabric with a slim, aerodynamic cut that adapts to your body and offers excellent protection against wind and cold. The Castelli Fly Jack-sey Black jacket features reflective details, three back pockets and a full front zipper. It is the ideal jacket for your cycling outings during the fall and winter months. Weight: 159g (M)