This is a very thin and lightweight shell.
It gives me very light wind protection. I wore it for 15 miles in a light rain and it kept me dry. When I got home, I could see that it was starting to come thru. I would say if you want to be just a tad warmer on chilly starts or a descent, this will work.
It will easily pack into a jersey pocket.
The zipper pulls pretty easily with one handed operation.
And despite Castelli's usually super small sizing, I was able to get by with a large. I'm 5'9 160lbs and usually wear a large in their jerseys, and I still have a little room with this over a jersey and arm warmers.
It will flap a bit at speeds over 25, but it's minimal.
Works best for cutting the wind and staying warm. Was good up to a point in 20 miles of heavy drizzlelight rain - by the end, water was starting to come thru. Excellent fit.
