Corrywrote a review of Castelli Velo Jacket - Men's on April 26, 2017
Familiarity: I've used it several times
I got this to fit in my pocket to use as needed for descending in cool weather or for rain. It packs up very small and is easy to fit in a pocket along with some grub or gloves. I haven't yet used it in the rain so I can't speak with experience as to how dry it might keep you, but my sense is that it would work in a light rain but be of little use in a downpour. It does keep the wind out without causing me to overheat. It has nice venting below the arms and down the back. My arms heat up in the jacket when working hard uphill but not too much. I'm very pleased with it so far.