Graham Dewartwrote a review of Castelli Perfetto RoS Convertible Jacket - Men's on November 29, 2019
Familiarity: I've used it several times
The Perfetto RoS Convertible Jacket is a solid choice for anyone looking for a layer for when it is in the 40's and may creep into the 50's. I wear a medium jersey in most brands and went for a medium in this. It fits but is race tight. For layering, I would order a size up.
The material is one in which it has some resistance to it, hence ROS, meaning rain or shine. This is a valuable component as it serves a dual purpose, blocking the wind and keeping you warm. I'm looking forward to using this jersey in multiple situations. One, for days where its in the 40's with a base layer underneath. Another, when its in the low 50's, or I know it will warm up and I will unzip the sleeves and use the jersey paired with a pair of arm warmers. This ability to have this jacket work in temperatures ranging from 40-55 is its greatest asset.