Technically, the Fiandre Light NoRain Vest is the least protective top of Sportful's Fiandre Light NoRain line--but that's only because it doesn't have sleeves. That means it's waterproof and blocks the wind across the torso, it's a little bit lighter (around 30g, claimed), and it's a helluva lot more packable than the short-sleeve Fiandre. It's also obviously more viable in warmer temps. That, combined with its packability, means you can stow it on days in late spring where you're climbing in sunshine but anticipate descending in cold rain and rapidly falling temperatures. The Fiandre Light Vest is equipped with the same wind- and waterproof fabric of its sleeved siblings, and the back panel between shoulders and pockets is a stretchy, DWR-treated fleece that improves breathability and stretch without sacrificing water-resistance. The stretch is especially important, because the Fiandre is a racing line, not a club fit one, so a bit of extra give in key areas provides a sleeker overall fit. Sportful classifies the Fiandre Light for use in 50 - 60 degrees Fahrenheit; however, we find that cyclists who tend to run hot can wear it with a light base layer into the mid-40s and a thermal base layer into the high-30s. That doesn't hold true for everyone, but it gives you an idea of what the vest is capable of, protection-wise. The vest's key feature is the weather-proofing, but we're going close with a discussion of pockets. Previous iterations only had a single rear pocket, but the new Fiandre Light tops include the standard complement of three, making them more viable for long training rides. We always found pockets a curious omission that held the Fiandre back from its true potential. Now, the only thing holding it back is weather too intense to justify riding in. Considering the above, that rules out everything but violent deluges and snowstorms.