Castelli made this short for spring conditions, when your riding goes from long winter rides in tights to higher intensity, and you're riding no matter the weather.
This short is made with Nano Light Pro fabric, an unbrushed version of their Nano Flex fabric. This fabric has a tighter weave so it keeps out more water, and the 270 g weight makes this good for cool weather as well as providing great muscle support.
Castelli have minimised the seams to help keep the water out and provided reflective logos for extra visibility. The KISS air pad is comfortable for your longest rides, and you won't even notice the low-profile gripper that keeps the leg in place.