Ready to move up to a better cool-weather jersey? The Tutto Nano RoS Jersey features a number of upgrades compared to what you've probably been using. First is the stretch fit that moves perfectly with you, made possible by the Nano Flex 3G fabric, the same fabric we use to make our arm and leg warmers as well as our Sorpasso tights. This close-to-body fit actually makes the jersey warmer by avoiding fabric flapping in the wind. Second is the tighter knit of the fabric compared to traditional thermal jersey fabrics. It lets less air through so you stay warmer. Next is Castelli's proprietary nanotechnology water-repellent finish. On dry days you won't even know it's there, but when you get some light rain or wet roads then you stay drier. Last is the 360° reflectivity, thanks to the panels on the shoulders and lower back. Of course, the Castelli attention to detail is there, with the easy-sliding YKK® Vislon® zipper with rubberized pull and the silicone gripper elastic to prevent the jersey from riding up.