Make no qualms about it, Castelli cares about the quality of your ride. That's why it decided to expand its Rosso Corsa line to include the new Flanders Base Layer. And to be certain that every climate is spoken for, it created both long and short sleeve iterations, and the Sleeveless version feature here. To start, the Flanders base layer features multiple fabrics in multiple locations. In other words, Castelli was dedicated to applying the right tool for the job. At the body, the base layer uses a multi denier multi weight polyester composition. This material was created with a rib knit, 3D structure that enhances mechanical moisture wicking, while also creating a stretchable, conforming fit around the torso. However, it's important to note that this design essentially creates channels that keep the fabric largely off of your skin. Ultimately, this reduces, if not eliminates, the threat of abrasion. At the underarms, a natural evacuation point for excess core heat exhaust, Castelli placed a perforated mesh polyester. And, as you probably guessed, perforation equates to ventilation. As a result, your body temperature remains well regulated, which prevents the threat of overheating. Further along with the construction, you'll find that Castelli only used four needle flatlock stitching throughout. This construction method equates to a lower profile seam and a flat stitch. And, as a result, the base layer lays closer to the body, which makes for increased moisture management and no chafing. Lastly, Castelli sought to ensure that your body obtains total coverage, and to do so, it incorporated a crew neck and an flat finish, elongated back. The Castelli Flanders Sleeveless Base Layer is available in the color White and in six sizes from X Small to XX Large. Please note that Castelli recommends this base layer for a temperature range of 57 to 69 degrees Fahrenheit.