The shortest version in this line of Castelli socks--Rossa Corsa is Castelli's designation for its best gear. The Rossa Corsa is woven with Meryl Skinlife antibacterial fibers to fight odors. The top of the foot is an open mesh to keep your foot as cool as possible. In the arch, Castelli wove a high-density band into the sock that holds the sock firmly in place while you ride. The sock also has a flat seam and the cuff is folded over to prevent slipping.