Right vest for the right price. I searched for a vest that fit like this for awhile. Snug fit without being too tight and does not flap in the wind. Even though I have a 42 chest I went with the Medium. Glad I did.
With the elastic panels on the sides it fits tighter than my previous Castelli yet seems to do a better job of protecting my previously fractured collar bone from the wind. I don't plan on testing it in the rain. It wads up into the size of half a banana has a back pocket which is not suitable for anything heavier than a route map. I would not expect, however, to be able to carry anything in a vest pocket made of a material this light.
This is a staple item for any rider. The full zip and lightweight windbreaker fabric allow for easy removal during a ride if temperatures climb. The high collar helps cut wind but folds nicely if you don't need it. Inside is mesh, outside is a non-transparent black windbreaker fabric. Elastic around the waist and arm holes. Once single pocket in the back. I got the blackgrey and I love the look. Essential for those early morning foggy rides.
Use it under my softshell in the cold weather, it works great and easy to pack if you need to dress down.