The Castelli’s Prologo 7 Long Sleeve Jersey blocks chilly wind and 97% of UV rays with a lightweight, breathable fabric. Air flows through the soft micro-piqué polyester keeping a cyclist from overheating. The jersey can be comfortably worn while riding in both mildly cool and warm weather. The neck protector and raw-cut sleeve endings are two more features to make the long sleeve jersey exceptionally comfortable. Castelli’s drop-pocket design places the rear pockets lower on the back for easier access, and they won’t bounce around when loaded with munchies. When it heats up, it’s easy to unzip the YKK Vislon zipper to let in cooling breeze. Reflective details on both sides of pocket provide illumination when the sun is down or covered by rain clouds. Add a heavier base layer and you will stay warn down to below 15°C/60°F. Add a vest and you can ride in even colder weather.