When we think about what we want in a cool-looking jacket, we keep coming back to the Perfetto, since it really is perfect for so many conditions. We just want it to look different. The Perfetto RoS 2 excels in dry conditions, thanks to the high breathability, as well as in wet conditions, thanks to the Castelli-exclusive GORE-TEX INFINIUM™ WINDSTOPPER® fabrics. There's a light fleece-lined water-resistant fabric on the forward-facing surfaces and a lighter and stretchier fabric on the back that maximizes breathability while providing excellent water repellency. The Perfetto RoS 2 Jacket keeps all the cold wind out while being much more breathable than the typical polyurethane membranes used on most jackets that try to compete with the Perfetto. When you stay drier, you don't need as many layers underneath. The beauty of this jacket is that it doesn't have any insulation on its own, so a thin base layer is just right for mild conditions, while adding an insulating layer (a thermal jersey or Castelli's Cold Days 2nd Layer) will take you to cold temperatures. You decide. The "2" in the name refers to the updates to the latest version, including a YKK® Vislon® zipper with both top and bottom openings for more adjustable ventilation. The reflectivity on the back is more visible, the seam at the top of the shoulder has been moved to the back, and the three pockets hold more gear. While the Perfetto retains a decidedly performance fit, the new model has a touch more room through the chest, shoulders, and biceps. This is the one jacket that belongs in every cyclist's quiver.