The Sottile jacket is a transparent rain cape and a classic racer's piece. Castelli was not satisfied with the thought of wearing an old-style rain cape that's essentially a plastic bag. So they made the Sottile breathable with a Transparent Compact waterproof membrane and added a bit of stretch. Then they made all the details just right, from the high collar to the zippered pocket opening. It is small enough to fit in half a jersey pocket.
We have found the Sottile Jackets run small. We suggest ordering the larger size if between sizes