The Perfetto RoS 2 Vest is Castelli's attempt at the perfect vest. It's warm and windproof yet breathable thanks to the Castelli-exclusive GORE-TEX Infinium Windstopper fabric on the front and the membrane-free Nano Flex stretch woven back fabric. It's splash resistant for wet roads or changing conditions. It's light and packable, easily fitting in a jersey pocket with room to spare. It has three rear pockets of its own and a two-way YKK Vislon zipper you can open it from the bottom to access gear in your jersey pockets. It has 360° reflectivity thanks to the reflective trim on the armholes and reflective band below the pockets. It fits close to body with a high collar that feels oh-so-comfy for cooler conditions. GORE-TEX Infinium WindstopperExperience total windproofness and maximum breathability for comfort in cool and windy conditions. The light, breathable membrane blocks the wind while allowing vapors to escape, keeping chill effects to a minimum. An additional layer is available in some GORE-TEX Infinium Windstopper products for more protection and insulation. Durable treatment to the outer layer provides a complete shield against the wind and is highly water resistant. Nano FlexCastelli take their thermal fleecy stretch Thermoflex fabric and coat it with millions of tiny nanofilaments to create the most water-repellent fabric finish ever. Drops of water stay as spherical balls on top of the fabric or bounce off the fabric without leaving a trace.