Fit was solid, a lot of breathability (is that a word) in the chest, but arms are insulated. Works perfectly in concert with the Specialized Gilet vest they sell. This keeps the arm nice and warm, but you will get wind to the chest. Like anything, it's a nice layer once you know how to layer it. I like this jersey for rides when I start in the morning and end in the afternoon once it's warmed up. I can ride early with the Gilet, then ditch that, it breaths great once things warm up.